ORCID Profile
0000-0003-4669-8769
Current Organisations
Auckland University of Technology
,
Sidra Medical and Research Center
,
The University of Auckland
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Publisher: Springer Science and Business Media LLC
Date: 07-1988
DOI: 10.1007/BF00333402
Abstract: Implementation of medical interventions may vary with organization and available capacity. The influence of this source of variability on the cost-effectiveness can be evaluated by computer simulation following a carefully designed experimental design. We used this approach as part of a national implementation study of ultrasonographic infant screening for developmental dysplasia of the hip (DDH). First, workflow and performance of the current screening program (physical examination) was analyzed. Then, experimental variables, i.e., relevant entities in the workflow of screening, were defined with varying levels to describe alternative implementation models. To determine the relevant levels literature and interviews among professional stakeholders are used. Finally, cost-effectiveness ratios (inclusive of sensitivity analyses) for the range of implementation scenarios were calculated. The four experimental variables for implementation were: 1) location of the consultation, 2) integrated with regular consultation or not, 3) number of ultrasound machines and 4) discipline of the screener. With respective numbers of levels of 3,2,3,4 in total 72 possible scenarios were identified. In our model experimental variables related to the number of available ultrasound machines and the necessity of an extra consultation influenced the cost-effectiveness most. Better information comes available for choosing optimised implementation strategies where organizational and capacity variables are important using the combination of simulation models and an experimental design. Information to determine the levels of experimental variables can be extracted from the literature or directly from experts.
Publisher: Elsevier
Date: 2004
Publisher: SAGE Publications
Date: 24-01-2014
Abstract: Nonketotic hyperglycinemia is an inborn error of glycine metabolism. It manifests mostly as an acute encephalopathy in the neonatal period, although later, atypical presentations have also been reported. Mutations in 3 different genes have been implicated in nonketotic hyperglycinemia. Here we report a novel mutation, c.2296G T (p.Gly766Cys), in exon 19 of the glycine decarboxylase ( GLDC) gene (Refseq accession number NM_000170.2) in a consanguineous Indian couple with a history of 4 neonatal deaths.
Publisher: Wiley
Date: 1991
Abstract: The clinical similarity with the X-linked muscular dystrophies and the uniqueness of the homology between the DMD-like and the 1.8 kb sequences at the carboxyterminal domain of the dystrophin gene led to the suggestion that this 6q sequence might be a strong candidate for one of the autosomal recessive muscular dystrophies. Thus, we tested, through linkage analysis, if 6q probes flanking the dystrophin-homologous sequence are linked to the gene responsible for limb-girdle dystrophy (LGMD). A total of 226 in iduals (57 patients and 169 unaffected relatives) from 19 large unrelated Brazilian families was studied. Results of two-point analysis excluded linkage with MYB (6q22-23) and ESR (6q24-q27) at 8 = 0.10 and with TCP1 (6q25-q27) at 0 = 0.05, indicating that the LGMD gene is not in the 6q23-q27 region. Therefore, the dystrophin-homologue sequence is not the gene responsible for LGMD.
Publisher: Informa UK Limited
Date: 09-1987
Publisher: Cambridge University Press (CUP)
Date: 09-12-2011
DOI: 10.1017/S0007114511005241
Abstract: Inflammatory bowel disease (IBD) is a collective term for conditions characterised by chronic inflammation of the gastrointestinal tract involving an inappropriate immune response to commensal micro-organisms in a genetically susceptible host. Previously, aqueous and ethyl acetate extracts of gold kiwifruit ( Actinidia chinensis ) or green kiwifruit ( A. deliciosa ) have demonstrated anti-inflammatory activity using in vitro models of IBD. The present study examined whether these kiwifruit extracts (KFE) had immune-modulating effects in vivo against inflammatory processes that are known to be increased in patients with IBD. KFE were used as a dietary intervention in IL-10-gene-deficient ( Il10 − / − ) mice (an in vivo model of IBD) and the C57BL/6J background strain in a 3 × 2 factorial design. While all Il10 − / − mice developed significant colonic inflammation compared with C57BL/6J mice, this was not affected by the inclusion of KFE in the diet. These findings are in direct contrast to our previous study where KFE reduced inflammatory signalling in primary cells isolated from Il10 − / − and C57BL/6J mice. Whole-genome gene and protein expression level profiling indicated that KFE influenced immune signalling pathways and metabolic processes within the colonic tissue however, the effects were subtle. In particular, expression levels across gene sets related to adaptive immune pathways were significantly reduced using three of the four KFE in C57BL/6J mice. The present study highlights the importance of investigating food components identified by cell-based assays with appropriate in vivo models before making dietary recommendations, as a food that looks promising in vitro may not be effective in vivo.
Publisher: Oxford University Press (OUP)
Date: 1994
DOI: 10.1093/HMG/3.3.523
Publisher: Elsevier BV
Date: 04-2010
DOI: 10.1016/J.HRTHM.2009.12.023
Abstract: Molecular autopsy in sudden unexplained death in the young (SUDY) victims cannot usually be performed if tissue suitable for DNA extraction is not retained at autopsy. The purpose of this study was to assess the feasibility and clinical value of posthumous genetic testing for long QT syndrome (LQTS) using residual material from the neonatal screening (Guthrie) card in SUDY victims. Twenty-one cases were investigated up to 13 years after death. Deaths occurred at <1 year in one, 1-18 years in 18, and 19-35 years in two patients. Guthrie cards were 3-39 years old. DNA was extracted, and licons corresponding to the coding regions of the LQTS genes 1, 2, 3, 5, and 6 underwent either denaturing high-performance liquid chromatography screening or direct DNA sequencing. Adequate DNA was extracted in every case, although repeated purification and lification was often required. Rare variants were detected in six of 19 cases undergoing diagnostic screening. Four (21%) are considered to be pathological and have been used for family screening: R243C and H455Y in KCNQ1 in 12-year-old and 13-year-old boys, respectively, and Q81H and S621R in KCNH2 in 21-month and 28-year-old females, respectively. Variants of uncertain significance were R1047L in KCNH2 in a 2-year-old girl and S38G in KCNE1 in a 19-month-old boy. Point mutation tests for previously identified familial LQTS mutations revealed a positive result in both cases: E146K in KCNQ1 and exon 6-4del in KCNH2. Residual material from Guthrie cards collected for newborn metabolic screening can be used as a reliable source of DNA for the posthumous diagnosis of LQTS decades after SUDY, although purification and lification of DNA is time intensive.
Publisher: Hindawi Limited
Date: 2011
DOI: 10.1155/2011/158086
Abstract: An amniotic fluid s le from an in vitro fertilized pregnancy was referred for cytogenetic analysis based on a Down syndrome screening risk of 1 : 21. Routine cytogenetic analysis showed a nonmosaic karyotype of 46,XX,r(21)(p11.2q22.3), with partial monosomy for chromosome 21 due to a ring chromosome replacing one of the normal homologues. Detailed ultrasound scanning for the remainder of the pregnancy did not reveal any unusual findings. Parental bloods showed that the mother was mosaic for the ring 21 with a karyotype of 46,XX,r(21)(p11.2q22.3)/46,XX and the father had an unrelated Robertsonian translocation, with a karyotype of 45,XY,rob(13 )(q10 q10). Microarray analysis of cultured amniocytes determined the extent of the deletion of chromosome 21 material in the ring. The parents were given genetic counselling, and a phenotypically normal female baby was delivered at term. This case highlights the importance of karyotyping as an initial step in the management of couples referred for in vitro fertilization.
Publisher: Elsevier BV
Date: 09-1990
DOI: 10.1016/0888-7543(90)90231-I
Abstract: We report a new locus, designated JC-1, which maps between the gene responsible for adrenal hypoplasia (AHC) and the gene that encodes glycerol kinase (GK) in Xp21.2-21.3. The probe identifying this locus was obtained by cloning the distal sequence of a junction fragment from a Duchenne muscular dystrophy (DMD) patient with a large deletion. Pulsed-field gel electrophoresis analysis shows that a region of at least 4 Mb separates the 3' end of the dystrophin gene and the closest distal marker to AHC, DXS28. This region of the human genome contains few genes whose deletion results in a clinical phenotype. JC-1 is a useful probe from which to initiate strategies directed at cloning the AHC and GK loci.
Publisher: Informa Healthcare
Date: 26-09-2007
DOI: 10.1517/17460441.2.10.1389
Abstract: Chemical genomics is a new and rapidly developing field. It refers to the use of cell-permeable small molecules, which are highly specific for their protein targets, in order to dissect biological pathways and to discover new drug leads. Small-molecule screening is usually limited to high-throughput approaches that use defined cell lines however, whole organism screening is gaining increasing attention. This review addresses the latter concept and highlights the advances in whole organism-based screening, with an emphasis on the use of the zebrafish (Danio rerio).
Publisher: Wiley
Date: 19-12-1988
DOI: 10.1016/0014-5793(88)80982-7
Abstract: We have examined dystrophin mRNA in embryonic, newborn and adult mouse skeletal muscle. A discrete nerve-independent increase in mRNA size was observed between embryonic and adult stages, indicating that a developmentally regulated mRNA isoform switch occurs in the expression of the Duchenne muscular dystrophy (DMD) gene in skeletal muscle. These distinct mRNAs are most likely generated via selection of alternative transcriptional start sites or RNA processing pathways. In addition, denervation of adult muscle was without effect on the expression pattern.
Publisher: Elsevier BV
Date: 2010
Publisher: Elsevier BV
Date: 02-2015
DOI: 10.1016/J.JOCN.2014.06.096
Abstract: The New Zealand Neuromuscular Disease Registry (NZ NMD Registry) is part of the TREAT NMD Alliance, an international network that provides infrastructure ensuring the most promising new therapies reach neuromuscular patients as quickly as possible. Its main aim is to ensure that the most promising new therapies reach patients as quickly as possible. From the perspective of researchers interested in trialling treatments it is useful to have data on the pool of potential research participants. From a patient's perspective it is important to know what trials they can take part in. Both of these require a confirmed molecular diagnosis in the patient. Some therapeutic strategies not only require knowledge of which gene is affected but are targeted at specific mutations within the gene. In reviewing data held in the NZ NMD Registry it was noted that, of those diagnosed with a genetic condition, only 51% have a confirmed molecular genetic diagnosis. This low rate of genetic diagnosis is a potential barrier to research participation but can be removed with improved genetic technology and with changes in knowledge about and attitudes towards genetic testing.
Publisher: Elsevier BV
Date: 12-2012
DOI: 10.1016/J.JOCN.2012.04.008
Abstract: The development of effective treatments for neuromuscular diseases is a significant challenge due to difficulties in identifying adequate numbers of patients for clinical trials. Low patient numbers in these rare diseases also has an effect when establishing sound clinical practices based on experience gained from patients with similar diagnosis. The Muscular Dystrophy Association of New Zealand (MDA), working in consort with interested clinicians has established the New Zealand Neuromuscular Disease (NZ NMD) Registry in order to help address these problems. The NZ NMD Registry is exceptional in that it comprises one registry for all neuromuscular conditions and will significantly benefit both patients with neuromuscular disease and their clinicians.
Publisher: Mary Ann Liebert Inc
Date: 03-2011
Publisher: Wiley
Date: 09-2011
DOI: 10.1002/BDRC.20213
Abstract: The modeling of human disease in the zebrafish (Danio rerio) is moving away from chemical mutagensis and transient downregulation using morpholino oligomers to more targeted and stable transgenic methods. In this respect, zinc finger nucleases offer a means of introducing mutations at targeted sites at high efficiency. We describe here the development of zinc finger nucleases and their general use in model systems with a focus on the zebrafish.
Publisher: Spandidos Publications
Date: 19-12-2011
Abstract: Some genes can encode multiple overlapping transcripts, and this can result in challenges in identifying transcript-specific developmental expression profiles where tools such as RNA in situ hybrisations are inapplicable. Given this difficulty, we have undertaken a preliminary analysis of the developmental expression profile of selected transcripts of the dystrophin and utrophin genes of the zebrafish (Danio rerio) by targeting unique and common regions of each of these transcripts. The dystrophin and utrophin genes of zebrafish were identified by bioinformatic analysis and the dystrophin gene predictions were confirmed by transcript sequencing. These data enabled primer pairs to be designed in order to determine the expression profiles of unique, but overlapping transcripts, throughout embryonic development using quantitative real time reverse transcription PCR (qRT-PCR). The data indicated the early expression of the short carboxyl-terminal dystrophin transcript, with expression of the full length muscle transcript occurring during myogenesis. Importantly, a composite of these two profiles appeared to comprise the major transcriptional load of the zebrafish dystrophin gene. In contrast, utrophin gene expression was dominated by the full length transcript throughout embryogenesis. The approach described here provided a means by which a gene's transcriptional complexity can be deconvoluted to reveal transcriptional ersity during embryogenesis. This approach, however, required the identification of unique regions for transcript-specific targeting, and an appreciation of alternative splicing events that may compromise the design of primers for qRT-PCR.
Publisher: BMJ
Date: 15-05-2009
Abstract: The recognition of the 17q21.31 microdeletion syndrome has been facilitated by high resolution microarray technology. Recent clinical delineation of this condition emphasises a typical facial appearance, cardiac and renal defects, and speech delay in addition to intellectual disability, hypotonia and seizures. We describe 11 previously unreported patients expanding the phenotypic spectrum to include aortic root dilatation, recurrent joint subluxation, conductive hearing loss due to chronic otitis media, dental anomalies, and persistence of fetal fingertip pads. Molecular analysis of the deletions demonstrates a critical region spanning 440 kb involving either partially or wholly five genes, CRHR1, IMP5, MAPT, STH, and KIAA1267. These data have significant implications for the clinical diagnosis and management of other in iduals with 17q21.31 deletions.
Publisher: Massachusetts Medical Society
Date: 23-06-2016
Publisher: Wiley
Date: 26-10-2015
DOI: 10.1007/S10545-015-9897-6
Abstract: Two male siblings from a consanguineous union presented in early infancy with marked truncal hypotonia, a general paucity of movement, extrapyramidal signs and cognitive delay. By mid-childhood they had made little developmental progress and remained severely hypotonic and bradykinetic. They developed epilepsy and had problems with autonomic dysfunction and oculogyric crises. They had a number of orthopaedic problems secondary to their hypotonia. Cerebrospinal fluid (CSF) neurotransmitters were initially normal, apart from mildly elevated 5-hydroxyindolacetic acid, and the children did not respond favourably to a trial of levodopa-carbidopa. The youngest died from respiratory complications at 10 years of age. Repeat CSF neurotransmitters in the older sibling at eight years of age showed slightly low homovanillic acid and 5-hydroxyindoleacetic acid levels. Whole-exome sequencing revealed a novel mutation homozygous in both children in the monoamine transporter gene SLC18A2 (p.Pro237His), resulting in brain dopamine-serotonin vesicular transport disease. This is the second family to be described with a mutation in this gene. Treatment with the dopamine agonist pramipexole in the surviving child resulted in mild improvements in alertness, communication, and eye movements. This case supports the identification of the causal mutation in the original case, expands the clinical phenotype of brain dopamine-serotonin vesicular transport disease and confirms that pramipexole treatment may lead to symptomatic improvement in affected in iduals.
Publisher: Elsevier BV
Date: 12-2015
DOI: 10.1016/J.JOCN.2015.04.016
Abstract: Merosin deficient congenital muscular dystrophy (MDC1A) is an autosomal recessive disorder characterized by mutations in the LAMA2 gene at chromosome 6q22-23. This gene spans 65 exons and encodes the α2 chain subunit of laminin-2. A variety of deletions, missense, nonsense and splice site mutations have been described in the LAMA2 gene, with resultant MDC1A. We describe a novel LAMA2 homozygous sequence variant in a Samoan patient with MDC1A and confirm its pathogenic effect with merosin immunohistochemistry on skeletal muscle biopsy. The likely effect of the sequence variant is modeled using in silico analysis.
Publisher: Wiley
Date: 12-2003
DOI: 10.1359/JBMR.2003.18.12.2095
Abstract: Homozygous mutations in TNFRSF11B, the gene encoding osteoprotegerin, were found in affected members from six of nine families with idiopathic hyperphosphatasia. The severity of the phenotype was related to the predicted effects of the mutations on osteoprotegerin function. Idiopathic hyperphosphatasia (IH) is a rare high bone turnover congenital bone disease in which affected children are normal at birth but develop progressive long bone deformities, fractures, vertebral collapse, skull enlargement, and deafness. There is, however, considerable phenotypic variation from presentation in infancy with severe progressive deformity through to presentation in late childhood with minimal deformity. Two recent reports have linked idiopathic hyperphosphatasia with deletion of, or mutation in, the TNFRSF11B gene that encodes osteoprotegerin (OPG), an important paracrine modulator of RANKL-mediated bone resorption. We studied subjects with a clinical diagnosis of IH and unaffected family members from nine unrelated families. Clinical, biochemical, and radiographic data were collected, and genomic DNA examined for mutations in TNFRSF11B. The relationship between the mutations, their predicted effects on OPG function, and the phenotype were then examined. Of the nine families studied, affected subjects from six were homozygous for novel mutations in TNFRSF11B. Their parents were heterozygous, consistent with autosomal recessive inheritance. Four of the six mutations occurred in the cysteine-rich ligand-binding domain and are predicted to disrupt binding of OPG to RANKL. Missense mutations in the cysteine residues, predicted to cause major disruption to the ligand-binding region, were associated with a severe phenotype (deformity developing before 18 months age and severe disability), as was a large deletion mutation. Non-cysteine missense mutations in the ligand-binding domain were associated with an intermediate phenotype (deformity recognized around the age of 5 years and an increased rate of long bone fracture). An insertion/deletion mutation at the C-terminal end of the protein was associated with the mildest phenotype. Mutations in TNFRSF11B account for the majority of, but not all, cases of IH, and there are distinct genotype-phenotype relationships.
Publisher: Springer Science and Business Media LLC
Date: 08-1991
DOI: 10.1038/352815A0
Abstract: Duchenne's muscular dystrophy (DMD), which affects one in 3,500 males, causes progressive myopathy of skeletal and cardiac muscles and premature death. One approach to treatment would be to introduce the normal dystrophin gene into diseased muscle cells. When pure plasmid DNA is injected into rodent skeletal or cardiac muscle, the cells express reporter genes. We now show that a 12-kilobase full-length human dystrophin complementary DNA gene and a 6.3-kilobase Becker-like gene can be expressed in cultured cells and in vivo. When the human dystrophin expression plasmids are injected intramuscularly into dystrophin-deficient mdx mice, the human dystrophin proteins are present in the cytoplasm and sarcolemma of approximately 1% of the myofibres. Myofibres expressing human dystrophin contain an increased proportion of peripheral nuclei. The results indicate that transfer of the dystrophin gene into the myofibres of DMD patients could be beneficial, but a larger number of genetically modified myofibres will be necessary for clinical efficacy.
Publisher: Wiley
Date: 13-10-2015
DOI: 10.1111/JCE.12827
Abstract: The accurate prediction of the risk of sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HCM) remains elusive. Corrected QT interval (QTc) duration is a known risk factor in various cardiac conditions. Single nucleotide polymorphisms (SNPs) have been linked to QTc length, and to SCD. Here we investigated the role of 21 candidate SNPs in QTc duration and SCD events in patients with HCM. This HCM registry-based study included patients with an ECG, medical history, first SCD event data, and DNA available. Each in idual SNP was assessed using logistic regression for associations with 2 outcomes: a prolonged QTc ( ≥440 milliseconds), and first SCD event (SCD, resuscitated cardiac arrest, and appropriate implantable cardioverter defibrillator (ICD) shock for ventricular fibrillation/ventricular tachycardia (VF/VT). In 272 HCM patients, there were 31 SCD events (8 SCD, 9 resuscitated cardiac arrest, 14 ICD shocks for VF/VT 11%). A QTc ≥ 500 milliseconds was associated with SCD events on multivariate analysis (odds ratio [OR] = 4.0, 95% confidence interval [CI], 1.19-12.02, P = 0.016). In 228 Caucasian patients, 2 SNPs in the NOS1AP gene (rs10494366 and rs12143842) were associated with a prolonged QTc after correction for multiple testing. This remained significant after adjustment for current age, sex, and ≥1 SCD risk factor (OR 1.59 per copy of the minor allele, 95% CI 1.08-2.39, P = 0.022, and OR 1.63, 95% CI 1.09-2.49, P = 0.020, respectively). No SNPs were directly associated with SCD events. SNPs in the NOS1AP gene influence QTc interval duration but we have not demonstrated a direct association with the risk of SCD.
Publisher: Cold Spring Harbor Laboratory
Date: 10-2009
DOI: 10.1101/PDB.PROT5314
Abstract: The zebrafish ( Danio rerio ) has emerged as a popular model species. The rapid development of zebrafish embryos provides opportunities for investigation of genes essential for developmental processes, the human counterparts of which might be implicated in diseases. Understanding when and where genes are expressed can facilitate greater understanding of their function, and also allow the genes to be manipulated by gene knockdown in temporally and spatially specific manners. Quantitative real-time polymerase chain reaction (qRT-PCR) is widely applied in gene expression studies. This protocol presents techniques to optimize RNA isolation from zebrafish embryos quality assessment and the use of multiple reference genes are also emphasized. The combined use of TRIzol extraction and column-based purification is strongly recommended, because the resulting RNA is of better quality than RNA isolated using either of those methods alone. The procedure can be performed in 2 d, with in idual stages taking up to 15 h to complete.
Publisher: Elsevier BV
Date: 10-2011
DOI: 10.1016/J.GENE.2011.06.028
Abstract: Pseudotrisomy 13 syndrome is characterised by holoprosencephaly with or without polydactyly, but with a normal karyotype. The genetic cause of this syndrome remains unclear, but it is thought to be autosomal recessive. In order to identify possible candidate genes, we identified regions of homozygosity in the DNA of an affected foetus, which was the seventh pregnancy of a healthy non-consanguineous Cook Island Maori couple this ethnic group derives from a small founder population. Several large regions of homozygosity were identified using a high density array. We excluded two candidate genes that lay within these regions, and suggest that Pseudotrisomy 13 syndrome might not be monogenic and that a larger cohort of patients should be analysed using high density dosage/SNP arrays as well as whole exome sequencing in order to clarify the genetic underpinning of this rare syndrome.
Publisher: Wiley
Date: 29-03-2010
DOI: 10.1111/J.1651-2227.2010.01683.X
Abstract: 13q deletion is a rare cause of ambiguous genitalia in the male newborn, and can be associated with mental retardation of varying degree, retinoblastoma, and malformations of the brain, eye, genitourinary and gastrointestinal tract, depending on the level of the deletion. We present a male neonate with ambiguous genitalia and IUGR with a 13q33.2 deletion, and a paternal balanced translocation. Microarray analysis found the genes involved to be on chromosome 13 in the region 102989254bp-109214509bp. This deletion encompasses the EFNB2 gene, which has been implicated in genital malformations in 13q deletion cases. We find a link between haploinsufficiency of the EFNB2 gene and the presence of ambiguous genitalia and hypospadia in patients with a 13q.33 deletion. This work emphasizes the importance of early diagnosis of this condition due to the link with mental retardation and the need for follow up and management.
Publisher: UPV/EHU Press
Date: 2011
Abstract: Intact zebrafish embryos were used as an in vivo animal model to investigate the role of Ca2+ signaling during the differentiation of slow muscle cells (SMCs) within forming skeletal muscle. Transgenic zebrafish were generated using an a-actin promoter that targeted apoaequorin expression specifically to muscle cells. Two distinct Ca2+ signaling periods (CSPs) were visualized in the developing SMCs: between ~17.5-19.5 hours post-fertilization (hpf) and after ~23 hpf, separated by a ~3.5 h Ca2+ signaling quiet period. Further spatial characterization of these Ca2+ signals using confocal fluorescent microscopy and calcium green-1 dextran as a reporter, indicated that the earlier CSP displayed distinct nuclear and cytoplasmic components, whereas the later CSP was predominantly cytoplasmic. Both CSPs consisted of a series of oscillating Ca2+ waves generated at distinct frequencies, while the earlier CSP also displayed a slow rise then fall in the Ca2+ baseline-level. Imaging of cyclopamine- and forskolin-treated wild-type, or smo-/- mutant embryos, where SMCs do not form, confirmed the specific cell population generating the signals. Treating embryos with antagonists indicated that both IP3Rs and RyRs are responsible for generating the temporal characteristics of the Ca2+ signaling signature, and that the latter plays a necessary role in SMC differentiation and subsequent myotome patterning. Together, these data support and extend the proposition that specific spatiotemporal patterns of spontaneous Ca2+ signals might be used for different as well as combinatorial regulation of both nuclear and cytosolic signal transduction cascades, resulting in myofibrillogenesis in SMCs as well as myotome patterning.
Publisher: Oxford University Press (OUP)
Date: 1992
DOI: 10.1093/HMG/1.8.579
Abstract: The gene loci for adrenal hypoplasia congenita (AHC) and glycerol kinase deficiency (GK) map in Xp21 distal to Duchenne muscular dystrophy (DMD), and proximal to DXS28 (C7), by analysis of patient deletions. We have constructed a yeast artificial chromosome (YAC) contig encompassing a 1.2 Mb region extending distally from DMD, and containing DXS708 (JC-1), the distal junction clone of a patient with GK and DMD. A pulsed-field gel electrophoresis map of the YAC contig identified 3 potential CpG islands. Whole YAC hybridization identified cosmids both for construction of cosmid contigs, and isolation of single copy probes. Thirteen new single copy probes and DXS28 and DXS708 were hybridized on a panel of patients the deletion mapping indicates that the YAC contig contains both GK and at least part of AHC, and together with the physical map defines a GK critical region of 50-250 kb. In one AHC patient with a cytogenetically detectable deletion we used the new probes to characterize a complex double deletion. Non-overlapping deletions observed in other unrelated AHC patients indicate that the AHC gene is large, extending over at least 200-500 kb. This mapping provides the basis for the identification of the AHC and GK genes.
Publisher: Elsevier BV
Date: 04-1991
DOI: 10.1016/0022-510X(91)90070-N
Abstract: Facioscapulohumeral muscular dystrophy (FSH) is an autosomal dominant condition with variable expressivity and age dependent penetrance. Linkage studies still did not exclude regions 11, 2q, 6q, 7p, 8p, 10q, 12p and 14p as possible locations for the FSH gene. In the present study we have analysed 80 in iduals (36 patients and 44 normals) belonging to 8 unrelated Brazilian families with 3 probes located on the long arm of chromosome 6:MHB(6q22-q23), ESR(6q24-q27) and TCP1(6q25-q27). Results of linkage analysis suggest that the gene responsible for FSH muscular dystrophy is not in the region 6q23-q27.
Publisher: Oxford University Press (OUP)
Date: 02-1999
DOI: 10.1093/HMG/8.2.353
Abstract: Emerin is a nuclear membrane protein which is missing or defective in Emery-Dreifuss muscular dystrophy (EDMD). It is one member of a family of lamina-associated proteins which includes LAP1, LAP2 and lamin B receptor (LBR). A panel of 16 monoclonal antibodies (mAbs) has been mapped to six specific sites throughout the emerin molecule using phage-displayed peptide libraries and has been used to localize emerin in human and rabbit heart. Several mAbs against different emerin epitopes did not recognize intercalated discs in the heart, though they recognized cardiomyocyte nuclei strongly, both at the rim and in intranuclear spots or channels. A polyclonal rabbit antiserum against emerin did recognize both nuclear membrane and intercalated discs but, after affinity purification against a pure-emerin band on a western blot, it stained only the nuclear membrane. These results would not be expected if immunostaining at intercalated discs were due to a product of the emerin gene and, therefore, cast some doubt upon the hypothesis that cardiac defects in EDMD are caused by absence of emerin from intercalated discs. Although emerin was abundant in the membranes of cardiomyocyte nuclei, it was absent from many non-myocyte cells in the heart. This distribution of emerin was similar to that of lamin A, a candidate gene for an autosomal form of EDMD. In contrast, lamin B1 was absent from cardiomyocyte nuclei, showing that lamin B1 is not essential for localization of emerin to the nuclear lamina. Lamin B1 is also almost completely absent from skeletal muscle nuclei. In EDMD, the additional absence of lamin B1 from heart and skeletal muscle nuclei which already lack emerin may offer an alternative explanation of why these tissues are particularly affected.
Publisher: Oxford University Press (OUP)
Date: 1989
DOI: 10.1093/NAR/17.1.439
Abstract: Trypanosoma secretome was shown to be involved in parasite virulence and is suspected of interfering in parasite life-cycle steps such as establishment in the Glossina midgut, metacyclogenesis. Therefore, we attempted to identify the proteins secreted by procyclic strains of T. brucei gambiense and T. brucei brucei, responsible for human and animal trypanosomiasis, respectively. Using mass spectrometry, 427 and 483 nonredundant proteins were characterized in T. brucei brucei and T. brucei gambiense secretomes, respectively 35% and 42% of the corresponding secretome proteins were specifically secreted by T. brucei brucei and T. brucei gambiense, respectively, while 279 proteins were common to both subspecies. The proteins were assigned to 12 functional classes. Special attention was paid to the most abundant proteases (14 families) because of their potential implication in the infection process and nutrient supply. The presence of proteins usually secreted via an exosome pathway suggests that this type of process is involved in trypanosome ESP secretion. The overall results provide leads for further research to develop novel tools for blocking trypanosome transmission.
Publisher: Wiley
Date: 07-01-2016
DOI: 10.1007/S10545-015-9911-Z
Abstract: Very long chain acyl-CoA dehydrogenase deficiency (VLCADD, OMIM #201475) has been increasingly diagnosed since the advent of expanded newborn screening (NBS). Elevated levels of tetradecenoyl-L-carnitine (C14:1) in newborn screening blood spot s les are particularly common in New Zealand, however this has not translated into increased VLCADD clinical presentations. A high proportion of screen-positive cases in NZ are of Maori or Pacific ethnicity and positive for the c.1226C > T (p.Thr409Met) ACADVL gene variant. We performed a retrospective, blinded, case-control study of 255 cases, born between 2006 and 2013, with elevated NBS C14:1 levels between 0.9 and 2.4 μmol/L, below the NZ C14:1 notification cut-off of 2.5 μmol/L. Coded healthcare records were audited for cases and age- and ethnicity- matched controls. The clinical records of those with possible VLCADD-related symptoms were reviewed. The follow-up period was 6 months to 7 years. Two of 247 cases (0.8 %) had possible VLCADD-like symptoms while four of 247 controls (2 %) had VLCADD-like symptoms (p = 0.81). Maori were overrepresented (68 % of the cohort vs 15 % of population). Targeted analysis of the c.1226 locus revealed the local increase in screening C14:1 levels is associated with the c.1226C > T variant (97/152 alleles tested), found predominantly in Maori and Pacific people. There was no increase in clinically significant childhood disease, irrespective of ethnicity. The study suggests that children with elevated C14:1, between 0.9-2.4 μmol/L, on NBS are at very low risk of clinically significant childhood disease. A minimally interventional approach to managing these patients is indicated, at least in the New Zealand population.
Publisher: Elsevier BV
Date: 2011
DOI: 10.1016/J.CELLIMM.2011.04.004
Abstract: Inflammatory bowel disease (IBD) is a chronic, inflammatory disorder of the gastrointestinal tract involving an inappropriate immune response to commensal microorganisms in a genetically susceptible host. This study examined the effects of aqueous and ethyl acetate extracts of gold kiwifruit (Actinidia chinensis) or green kiwifruit (Actinidia deliciosa) using in vitro models of IBD. These models comprised primary macrophages and intestinal epithelial cells isolated from C57BL/5J and interleukin-10 gene deficient (Il10(-/-)) mice and RAW 264.7, a murine macrophage-like cell line. All four kiwifruit extracts reduced the activation of these models after lipopolysaccharide stimulation, decreasing nitric oxide and cytokine secretion by both Il10(-/-) and wild-type cells. The ethyl acetate extracts exhibited the highest anti-inflammatory activity, with almost complete suppression of lipopolysaccharide-stimulated macrophage activation. These results suggest that kiwifruit extracts have significant anti-inflammatory activity relevant to IBD. We suggest that the Il10(-/-) mouse is a suitable model for further study of these compounds.
Publisher: Oxford University Press (OUP)
Date: 1992
DOI: 10.1093/HMG/1.1.35
Abstract: Duchenne and the less severe Becker form of muscular dystrophy (DMD,BMD) result from genetic deficiency in the level and/or activity of the protein dystrophin. The recent availability of cDNA based minigenes encoding recombinant dystrophin polypeptides has raised the possibility of somatic gene transfer as a therapeutic approach to treat dystrophin deficiency. In this respect, the mdx mouse provides a useful model of DMD exhibiting features characteristic of both the early myopathic and later fibrotic phases of the human disease. Using a mutated human cDNA, compatible in size with virus-based somatic gene transfer vectors, the pathophysiological consequences of restoring dystrophin expression have been examined in transgenic mdx mice. Transgene expression was correlated with a marked reduction of the skeletal myofibre necrosis and regeneration which is a major feature of the dystrophin-deficient phenotype in young mdx mice. The cDNA construct which is based on a very mild BMD phenotype thus encodes a highly functional dystrophin molecule whose reduced size renders it an attractive candidate for development as a therapeutic gene transfer reagent.
Publisher: Wiley
Date: 20-01-1992
DOI: 10.1016/0014-5793(92)80363-L
Abstract: We have demonstrated expression of a 6.3 kb Becker muscular dystrophy (BMD) human dystrophin cDNA following retroviral-mediated transduction of cultured myoblasts from the dystrophin-deficient mdx mouse. The truncated dystrophin protein was localised to the sarcolemma of differentiated myotubes by antibodies against the C-terminus of the molecule, and produced an identical immunostaining pattern to that observed in control myotubes expressing normal endogenous dystrophin. These results indicate that retroviral-mediated gene transfer may be useful for experimental in vivo studies on the complementation of dystrophin gene mutations.
Publisher: Spandidos Publications
Date: 13-06-2013
Abstract: The aim of the present study was to evaluate the use of KaryoLite™ bacterial artificial chromosomes (BACs)‑on‑Beads™ (BoBs) technology for the rapid screening of products of conception (POC). Validation and prospective studies were carried out on 85 and 95 patient s les, respectively. Validation studies had previously been analyzed using routine culture and G-banded karyotyping. BoBs resulted in an abnormality detection frequency of 27%, with a failure rate of <3%. The time required for processing was significantly lower compared with that of tissue culture. In conclusion, BoBs technology decreased the failure rate, while increasing the analytical sensitivity compared with G-banded karyotype analysis alone. Additionally, significant cost savings may be achieved with regard to the time of processing and analysis of specimens.
Publisher: Wiley
Date: 26-03-1990
DOI: 10.1016/0014-5793(90)80199-S
Abstract: Nineteen monoclonal antibodies which bind to native dystrophin in the plasma membrane of frozen muscle sections were obtained using a recombinant fusion protein as immunogen. On Western blots of normal mouse muscle extracts, the antibodies bind specifically to a 400,000 Mr protein which is absent from dystrophic mouse (mdx) muscle. At least four distinct epitopes have been identified by cleavage mapping methods. Although the fusion protein contained 25% of the human dystrophin sequence (Cys816-Asp1747 Mr 108,000), most of the monoclonal antibodies (15 out of 19) recognize a single fragment of Mr 27,500.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 2010
Publisher: Elsevier BV
Date: 08-2001
Publisher: Uppsala Medical Society
Date: 02-04-2015
Publisher: Springer Science and Business Media LLC
Date: 08-2001
Publisher: Hindawi Limited
Date: 2012
DOI: 10.1155/2012/350352
Abstract: The zebrafish ( Danio rerio ) has become an attractive model for human disease modeling as there are a large number of orthologous genes that encode similar proteins to those found in humans. The number of tools available to manipulate the zebrafish genome is limited and many currently used techniques are only effective during early development (such as morpholino-based antisense technology) or it is phenotypically driven and does not offer targeted gene knockdown (such as chemical mutagenesis). The use of RNA interference has been met with controversy as off-target effects can make interpreting phenotypic outcomes difficult however, this has been resolved by creating zebrafish lines that contain stably integrated miRNA constructs that target the desired gene of interest. In this study, we show that a commercially available miRNA vector system with a mouse-derived miRNA backbone is functional in zebrafish and is effective in causing eGFP knockdown in a transient in vivo eGFP sensor assay system. We chose to apply this system to the knockdown of transcripts that are implicated in the human cardiac disorder, Long QT syndrome.
Publisher: S. Karger AG
Date: 2012
DOI: 10.1159/000335344
Abstract: The relatively rare proximal microdeletion of 17q12 (including deletion of the i HNF1B /i gene) is associated with the renal cysts and diabetes syndrome. Recent reports have suggested that there may also be an association between this microdeletion and learning difficulties/autism. This case report describes one of only a few reported families segregating the 17q12 microdeletion, but which highlights the nonpenetrance and variable expressivity of multiple features of this condition.
Publisher: Wiley
Date: 25-03-2010
Publisher: Elsevier BV
Date: 2014
DOI: 10.1016/J.HRTHM.2013.10.005
Abstract: Disease-modifying single nucleotide polymorphisms (SNPs) can help explain incomplete penetrance and variable expressivity in congenital long QT syndrome (LQTS) by altering susceptibility to arrhythmias. The purpose of this study was to assess multiple arrhythmia SNPs (in 16 genes) in a distinct cohort of LQTS patients to identify modifier SNPs influencing the risk of sudden death. This study included 273 patients with LQTS from the New Zealand Cardiac Inherited Disease Registry (154 long QT type 1, 96 long QT type 2, and 23 long QT type 3), including 31 patients who had experienced death or resuscitated sudden cardiac death (RSCD). Patients were genotyped for 29 SNPs and tested for associations with clinical events and QTc length. Caucasian (n = 220) and Pacific Islander/New Zealand Maori (n = 53) ethnic groups were analyzed separately. This subgroup of Polynesian ancestry has not been previously studied for LQTS in either presentation or outcome. In Caucasians, four SNPs at two risk loci (NOS1AP: rs12143842 and rs16847548 and KCNQ1: rs10798 and rs8234) were significantly associated with clinical events after correction for multiple testing. Patients homozygous for the risk allele of rs12143842 had an increased risk of death/RSCD [hazard ratio 10.15, 95% confidence interval (2.38, 43.34), q = 0.045). Several other SNPs showed trends toward association with QTc length and clinical events. This study demonstrates that SNPs in NOS1AP and KCNQ1 are associated with an increased risk of cardiac events in LQTS patients, with the hazard ratio suggesting they have significant potential in clinical risk stratification.
Publisher: BMJ
Date: 04-03-2014
Publisher: Wiley
Date: 10-12-2004
Publisher: Elsevier BV
Date: 12-1970
DOI: 10.1016/S0006-291X(03)00355-3
Abstract: The zebrafish is an established model of vertebrate development and is also receiving increasing attention in terms of human disease modelling. In order to provide experimental support to realize this modelling potential, we report here the identification of apparent orthologues of many critical members of the dystrophin-associated glycoprotein complex (DGC) that have been implicated in a erse range of neuromuscular disorders. In addition, immunohistochemical studies show the localization of the DGC to the sarcolemma of adult zebrafish muscle and in particular the myosepta. Together, these data suggest that the DGC in adult zebrafish may play a highly conserved functional role in muscle architecture that, when disrupted, could offer insight into human neuromuscular disease processes.
Publisher: Hindawi Limited
Date: 24-05-2016
DOI: 10.1155/2016/5614058
Abstract: The increasing diagnostic use of gene sequencing has led to an expanding dataset of novel variants that lie within consensus splice junctions. The challenge for diagnostic laboratories is the evaluation of these variants in order to determine if they affect splicing or are merely benign. A common evaluation strategy is to use in silico analysis, and it is here that a number of programmes are available online however, currently, there are no consensus guidelines on the selection of programmes or protocols to interpret the prediction results. Using a collection of 222 pathogenic mutations and 50 benign polymorphisms, we evaluated the sensitivity and specificity of four in silico programmes in predicting the effect of each variant on splicing. The programmes comprised Human Splice Finder (HSF), Max Entropy Scan (MES), NNSplice, and ASSP. The MES and ASSP programmes gave the highest performance based on Receiver Operator Curve analysis, with an optimal cut-off of score reduction of 10%. The study also showed that the sensitivity of prediction is affected by the level of conservation of in idual positions, with in silico predictions for variants at positions - 4 and +7 within consensus splice sites being largely uninformative.
Publisher: Elsevier BV
Date: 10-2004
DOI: 10.1016/J.DDTEC.2004.06.005
Abstract: Microarray technology allows the simultaneous changes in multiple gene expression to be determined as part of a drug discovery platform, or to understand the biological mechanisms of disease. In terms of both of these objectives, those studying the zebrafish as a complement to mouse-based research are only now able to entertain the construction of microarrays due to recent progress in sequencing the zebrafish genome. The advantage of the late entry of zebrafish to the microarray field offers the means of immediately adopting best practice, while also appreciating that what is currently on offer can be improved.:
Publisher: Springer Science and Business Media LLC
Date: 22-03-2012
DOI: 10.1007/S10895-012-1043-3
Abstract: Real-time in vivo imaging of cell migration and behavior has advanced our understanding of physiological processes in situ, especially in the field of immunology. We carried out the transplantation of a mixed population of blood cells from adult zebrafish (Danio rerio) to 2 day old embryos. The blood cells were treated ex vivo with Function-Spacer-Lipid constructs (FSL) incorporating either fluorescein or Atto488 fluorophores (FSL-FLRO4-I or -II). Excellent labeling efficiency was demonstrated by epifluorescence microscopy and FACScan analysis. Real-time video imaging of the recipient fish showed that the functionality of these cells was retained and not affected by the labeling. The usefulness of FSL-FLRO4-I as a contrast agent in microangiography was explored. Overall, we found both FSL-FLRO4-I and-II promising labeling dyes for real-time in vivo imaging in zebrafish.
Publisher: Springer Science and Business Media LLC
Date: 08-1990
DOI: 10.1007/BF00206755
Publisher: Wiley
Date: 27-12-2011
DOI: 10.1111/J.1440-1681.2011.05582.X
Abstract: 1. Evidence is accumulating for a role for Ca²⁺ signalling in the differentiation and development of embryonic skeletal muscle. 2. Imaging of intact, normally developing transgenic zebrafish that express the protein component of the Ca²⁺-sensitive complex aequorin, specifically in skeletal muscle, show that two distinct periods of spontaneous synchronised Ca²⁺ transients occur in the trunk: one at approximately 17.5-19.5 h post-fertilization (h.p.f. termed signalling period SP1) and the other after approximately 23 h.p.f. (termed SP2). These periods of intense Ca²⁺ signalling activity are separated by a quiet period. 3. Higher-resolution confocal imaging of embryos loaded with the fluorescent Ca²⁺ reporter calcium green-1 dextran shows that the Ca²⁺ signals are generated almost exclusively in the slow muscle cells, the first muscle cells to differentiate, with distinct nuclear and cytoplasmic components. 4. Here, we show that coincidental with the SP1 Ca²⁺ signals, dystrophin becomes localized to the vertical myoseptae of the myotome. Introduction of a dmd morpholino (dmd-MO) resulted in no dystrophin being expressed in the vertical myoseptae, as well as a disruption of myotome morphology and sarcomere organization. In addition, the Ca²⁺ signalling signatures of dmd-MO-injected embryos or homozygous sapje mutant embryos were abnormal such that the frequency, litude and timing of the Ca²⁺ signals were altered compared with controls. 5. Our new data suggest that, in addition to a structural role, dystrophin may function in the regulation of [Ca²⁺](i) during the early stages of slow muscle cell differentiation when the Ca²⁺ signals generated in these cells coincide with the first spontaneous contractions of the trunk.
Publisher: Springer Science and Business Media LLC
Date: 13-05-2015
Publisher: Elsevier BV
Date: 06-1996
DOI: 10.1016/0306-4522(95)00595-1
Abstract: The expression of enkephalin and substance P messenger RNAs was examined in the caudate-putamen of human post mortem tissue from control and Huntington's disease tissue using in situ hybridization techniques and human specific enkephalin and substance P [35S] oligonucleotides. Macroscopic and microscopic quantification of enkephalin and substance P gene expression was carried out using computer-assisted image analysis. Tissue was collected from six control cases with no sign of neurological disease and six Huntington's disease cases ranging from grades 0 to 3 as determined by neuropathological evaluation. The clinical and pathological diagnosis of Huntington's disease was confirmed unequivocally by genetic analysis of the CAG repeat length in both copies of IT15, the Huntington's disease gene. A marked reduction in both enkephalin and substance P messenger RNAs was detected in all regions of the caudate nucleus and putamen in Huntington's disease grades 2/3 when compared to controls in the dorsal caudate few enkephalin or substance P messenger RNA-positive cells were detected. For the early grade (0/1) Huntington's disease cases, a heterogeneous reduction in both enkephalin and substance P messenger RNAs were noted for enkephalin messenger RNA the striatal autoradiograms displayed a conspicuous patchy appearance. Detailed cellular analysis of the dorsal caudate revealed a striking reduction in the number of enkephalin and substance P messenger RNA-positive cells detected and in the intensity of hybridization signal/cell. These data suggest that both the "indirect" GABA/enkephalin and "direct" GABA/substance P pathways are perturbed very early in the course of the disease and that these early changes in chemical signalling may possibly underlie the onset of clinical symptoms.
Publisher: Hindawi Limited
Date: 11-11-2013
DOI: 10.1155/2013/857564
Abstract: Myotonic dystrophy type 1 is an autosomal dominant neuromuscular disorder that is caused by the expansion of a CTG trinucleotide repeat in the DMPK gene. The confirmation of a clinical diagnosis of DM-1 usually involves PCR lification of the CTG repeat-containing region and subsequent sizing of the lification products in order to deduce the number of CTG repeats. In the case of repeat hyperexpansions, Southern blotting is also used however, the latter has largely been superseded by triplet repeat-primed PCR (TP-PCR), which does not yield a CTG repeat number but nevertheless provides a means of stratifying patients regarding their disease severity. We report here a combination of forward and reverse TP-PCR primers that allows for the simple and effective scoring of both the size of smaller alleles and the presence or absence of expanded repeat sequences. In addition, the CTG repeat-containing TP-PCR forward primer can target both the DM-1 and Huntington disease genes, thereby streamlining the work flow for confirmation of clinical diagnoses in a diagnostic laboratory.
Publisher: Elsevier BV
Date: 12-2004
DOI: 10.1016/J.COPBIO.2004.09.004
Abstract: The zebrafish is a popular vertebrate model organism with similar organ systems and gene sequences to humans. Zebrafish embryos are optically transparent enabling organ visualisation, which can be complemented with gene expression analysis at the transcript and protein levels. Furthermore, zebrafish can be treated with small molecules and drugs in a microtitre plate format for high-throughput analysis and for the identification and validation of drugs. High-throughput methodologies for use in zebrafish include phenotype-based visualisation, transcript studies using low-density DNA microarrays and proteomic analysis. These technologies offer significant whole-organism biological value in the drug discovery and drug development pipeline.
Publisher: Elsevier BV
Date: 06-1998
DOI: 10.1016/S0306-4522(98)00129-8
Abstract: Recent studies using DNA fragmentation assays suggest a role for apoptosis in cell death in Huntington's disease. In this study, we investigated the relationship between the degree of DNA fragmentation and the number of trinucleotide (CAG) repeats of the Huntington's disease gene in striatal tissue from Huntington's disease brains. We used frozen striatal tissue from 27 post mortem Huntington's disease brains (graded 0-4 on the Vonsattel classification, post mortem delay ranging from 4 to 41 h), plus control sections which were age, sex and post mortem delay matched from neurologically normal and Alzheimer's diseased striatal tissue. Our results show a significant positive correlation between the number of CAG repeats in the Huntington's disease gene and the degree of DNA fragmentation in Huntington's disease striatum. These results suggest that expanded CAG repeats in the Huntington's disease gene may lead to neuronal degeneration in Huntington's disease through an apoptotic mechanism.
Publisher: Elsevier BV
Date: 1993
DOI: 10.1016/0960-8966(93)90037-K
Abstract: The analysis of dystrophin gene expression has led to the identification of multiple transcripts and varying isoforms. The data indicate that transcription of the dystrophin gene occurs from several promoters, which involves developmental and tissue-dependent regulation. These discoveries have complicated the interpretation of immunolocalization studies, although there is a strong correlation between the amount and size of dystrophin and the severity of the clinical phenotype. The importance of using protein-specific antibodies for dystrophin analysis has been underscored by the identification of a protein, designated utrophin, which exhibits significant sequence homology with dystrophin. This review addresses the recent studies of dystrophin and utrophin expression in an attempt to illustrate the transcriptional ersity of these large genes and the localization of their protein products within various tissues.
Publisher: Springer Science and Business Media LLC
Date: 12-1987
DOI: 10.1007/BF00327202
Abstract: Peripheral arterial disease (PAD) is common in hemodialysis patients and predicts a poor prognosis. We conducted a prospective cohort study to identify risk factors for PAD including skin perfusion pressure (SPP) in hemodialysis patients. The cohort included 373 hemodialysis patients among 548 patients who received hemodialysis at Oyokyo Kidney Research Institute, Hirosaki, Japan from August 2008 to December 2010. The endpoints were lower limb survival (peripheral angioplasty or utation events) and overall survival of 2 years. Our results showed that <70 mmHg SPP was a poor prognosis for the lower limb survival and overall survival. We also identified age, history of cardiovascular disease, presence of diabetes mellitus, smoking history, and SPP < 70 mmHg as independent risk factors for lower limb survival and overall survival. Then, we constructed risk criteria using the significantly independent risk factors. We can clearly stratify lower limb survival and overall survival of the hemodialysis patients into 3 groups. Although the observation period is short, we conclude that SPP value has the potential to be a risk factor that predicts both lower limb survival and the prognosis of hemodialysis patients.
Publisher: Springer Science and Business Media LLC
Date: 19-12-2013
Abstract: Maturity-Onset Diabetes of the Young (MODY) is a monogenic form of diabetes, consisting of a heterogeneous group of autosomal dominant inherited disorders. Typical onset is in in iduals prior to twenty five years, and presentation can mimic type 1 or 2 diabetes. Molecular genetic testing can allow precise identification of the different MODY sub-types. Making a specific diagnosis of MODY can have important implications for the guidance of appropriate treatment, prognosis and genetic counselling. We present the cases of three children and their families diagnosed with MODY over the past two years. These families highlight the features of three of the more common MODY subtypes, including two with novel mutations, one of which segregates in a kindred that is strongly affected by both MODY and classic autoimmune mediated diabetes. To date, we have identified a prevalence of MODY in the paediatric diabetes population of the lower South Island, New Zealand, of approximately 2.5%. This prevalence, along with increasing access to molecular genetic testing, highlights the importance of consideration of MODY in atypical diabetes presentations in the paediatric/adolescent population.
Publisher: Elsevier BV
Date: 04-2011
DOI: 10.1016/J.HRTHM.2010.11.039
Abstract: The potassium channel I(Ks), which is encoded by the KCNQ1 gene, is expressed in organ systems including the inner ear, kidneys, lungs, intestine, and stomach in addition to the heart. Increasing evidence indicates that I(Ks) in the stomach plays an essential role in enabling gastric acid production. It is not known whether gastric acid production is disordered in patients with long QT type 1. Serum gastrin levels become elevated in subjects with disordered gastric acid production. The purpose of this study was to evaluate serum gastrin levels, as a surrogate for impaired gastric acid secretion, in patients with KCNQ1 mutations, and to see if gastrin levels correlate with severity of cardiac disease. Fasting serum gastrin levels were measured using a standardized immunometric technique in an index case and 12 subjects with known KCNQ1 mutations. An adult female with Jervell and Lange-Nielsen syndrome (JLNS with KCNQ1 nonsense mutations p.Arg518X and p.Arg190AlafsX95 ) presented with multiple gastric carcinoid tumors and grossly elevated serum gastrin levels (943-1,570 pmol/L normal 6-55 pmol/L) and absent acid secretion. Gastrin levels in two girls with JLNS, unrelated to the index case (missense mutations p.Leu266Pro and Gly269Ser), also were high (305 and 229 pmol/L). Gastrin levels were normal in 10 KCNQ1 heterozygous single mutation carriers, even in those with severe long QT syndrome, including three heterozygous family members of the JLNS subjects. JLNS may be associated with elevated gastrin levels, impaired acid secretion, and risk of gastric carcinoid tumors. Among KCNQ1 single mutation carriers, gastrin levels were normal and did not appear to be linked to the severity of clinical expression of long QT syndrome.
Publisher: Springer Science and Business Media LLC
Date: 31-07-2003
DOI: 10.1038/NBT852
Publisher: Hindawi Limited
Date: 07-02-2013
DOI: 10.1155/2013/908317
Abstract: Purpose . The aim of this study was to develop a streamlined mutation screening protocol for the DMD gene in order to confirm a clinical diagnosis of Duchenne or Becker muscular dystrophy in affected males and to clarify the carrier status of female family members. Methods . Sequence analysis and array comparative genomic hybridization (aCGH) were used to identify mutations in the dystrophin DMD gene. We analysed genomic DNA from six in iduals with a range of previously characterised mutations and from eight in iduals who had not previously undergone any form of molecular analysis. Results . We successfully identified the known mutations in all six patients. A molecular diagnosis was also made in three of the four patients with a clinical diagnosis who had not undergone prior genetic screening, and testing for familial mutations was successfully completed for the remaining four patients. Conclusion . The mutation screening protocol described here meets best practice guidelines for molecular testing of the DMD gene in a diagnostic laboratory. The aCGH method is a superior alternative to more conventional assays such as multiplex ligation-dependent probe lification (MLPA). The combination of aCGH and sequence analysis will detect mutations in 98% of patients with the Duchenne or Becker muscular dystrophy.
Publisher: Mary Ann Liebert Inc
Date: 19-03-2000
Abstract: PCR lification of the CAG repeat in exon 1 of the IT15 gene is routinely undertaken to confirm a clinical diagnosis of Huntington disease (HD) and to provide predictive testing for at-risk relatives of affected in iduals. Our studies have detected null alleles on the chromosome carrying the expanded repeat in three of 91 apparently unrelated HD families. Sequence analysis of these alleles has revealed the same mutation event, leading to the juxtaposition of uninterrupted CAG and CCG repeats. These data suggest that a mutation-prone region exists in the IT15 gene bounded by the CAG and CCG repeats and that caution should be exercised in designing primers that anneal to the region bounded by these repeats. Two of the HD families segregated null alleles with expanded uninterrupted CAG repeats at the lower end of the zone of reduced penetrance. The expanded repeats are meiotically unstable in these families, although this instability is within a small range of repeat lengths. The haplotypes of the disease-causing chromosomes in these two families differ, only one of which is similar to that reported previously as being specific for new HD mutations. Finally, no apparent mitotic instability of the uninterrupted CAG repeat was observed in the brain of one of the HD in iduals.
Publisher: Elsevier BV
Date: 08-2008
Publisher: Springer Science and Business Media LLC
Date: 1995
DOI: 10.1038/NG0195-75
Abstract: Nemaline myopathies are diseases characterized by the presence in muscle fibres of pathognomonic rod bodies. These are composed largely of alpha-actinin and actin. We have identified a missense mutation in the alpha-tropomyosin gene, TPM3, which segregates completely with the disease in a family whose autosomal dominant nemaline myopathy we had previously localized to chromosome 1p13-q25. The mutation substitutes an arginine residue for a highly conserved methionine in a putative actin-binding site near the N terminus of the alpha-tropomyosin. The mutation may strengthen tropomyosin - actin binding, leading to rod body formation, by adding a further basic residue to the postulated actin-binding motif.
Publisher: Bentham Science Publishers Ltd.
Date: 04-2014
Publisher: Oxford University Press (OUP)
Date: 1992
DOI: 10.1093/HMG/1.2.103
Abstract: The 14kb dystrophin transcript from the Duchenne muscular dystrophy (DMD) locus, which encodes a 427kDa protein, is differentially spliced at the amino terminal end giving rise to alternative transcripts expressed in muscle and brain. Here we present evidence for a 4.8kb transcript from the DMD locus which is ubiquitously expressed but is particularly abundant in Schwannoma cells where dystrophin could not be detected. The hybridisation of Western blots with dystrophin antibodies also identifies a protein of approximately 80kDa of variable abundance in different human and mdx tissues. Immunocytochemistry studies confirm the expression of this protein in nerve cells, a tissue in which full length dystrophin is not detected. Sequencing of the 5' end of a clone isolated from a rat Schwannoma cDNA library, shows that the 4.8kb transcript shares exons with the carboxy terminal end of dystrophin but the 5' untranslated region is not contained within the dystrophin transcript. We propose that the 4.8kb gene product be called apodystrophin-1 as its expression is distinct from the dystrophin 14kb mRNA but it is transcribed from the same locus.
Publisher: Elsevier BV
Date: 08-1999
Publisher: Elsevier BV
Date: 12-2009
Publisher: Elsevier BV
Date: 04-2015
DOI: 10.1016/J.AHJ.2014.11.015
Abstract: There is a genetic contribution to the risk of ventricular arrhythmias in survivors of acute coronary syndromes (ACS). We wished to explore the role of 33 candidate single nucleotide polymorphisms (SNPs) in prolonged repolarization and sudden death in patients surviving ACS. A total of 2,139 patients (1680 white ethnicity) surviving an admission for ACS were enrolled in the prospective Coronary Disease Cohort Study. Extensive clinical, echocardiographic, and neurohormonal data were collected for 12 months, and clinical events were recorded for a median of 5 years. Each SNP was assessed for association with sudden cardiac death (SCD)/cardiac arrest (CA) and prolonged repolarization at 3 time-points: index admission, 1 month, and 12 months postdischarge. One hundred six SCD/CA events occurred during follow-up (6.3%). Three SNPs from 3 genes (rs17779747 [KCNJ2], rs876188 [C14orf64], rs3864180 [GPC5]) were significantly associated with SCD/CA in multivariable models (after correction for multiple testing) the minor allele of rs17779747 with a decreased risk (hazard ratio [HR] 0.68 per copy of the minor allele, 95% CI 0.50-0.92, P = .012), and rs876188 and rs386418 with an increased risk (HR 1.52 [95% CI 1.10-2.09, P = .011] and HR 1.34 [95% CI 1.04-1.82, P = .023], respectively). At 12 months postdischarge, rs10494366 and rs12143842 (NOS1AP) were significant predictors of prolonged repolarization (HR 1.32 [95% CI 1.04-1.67, P = .022] and HR 1.30 [95% CI 1.01-1.66, P = .038], respectively), but not at earlier time-points. Three SNPs were associated with SCD/CA. Repolarization time was associated with variation in the NOS1AP gene. This study demonstrates a possible role for SNPs in risk stratification for arrhythmic events after ACS.
Publisher: Elsevier BV
Date: 09-2008
DOI: 10.1016/J.HRTHM.2008.05.033
Abstract: Sequencing or denaturing high-performance liquid chromatography (dHPLC) analysis of the known genes associated with the long QT syndrome (LQTS) fails to identify mutations in approximately 25% of subjects with inherited LQTS. Large gene deletions and duplications can be missed with these methodologies. The purpose of this study was to determine whether deletions and/or duplications of one or more exons of the main LQTS genes were present in an LQTS mutation-negative cohort. Multiplex ligation-dependent probe lification (MLPA), a quantitative fluorescent approach, was used to screen 26 mutation-negative probands with an unequivocal LQTS phenotype (Schwartz score >4). The appropriate MLPA kit contained probes for selected exons in LQTS genes KCNQ1, KCNH2, SCN5A, KCNE1, and KCNE2. Real-time polymerase chain reaction was used to validate the MLPA findings. Altered exon copy number was detected in 3 (11.5%) patients: (1) an ex13-14del of the KCNQ1 gene in an 11-year-old boy with exercise-induced collapse (QTc 580 ms) (2) an ex6-14del of the KCNH2 gene in a 22-year-old woman misdiagnosed with epilepsy since age 9 years (QTc 560 ms) and a sibling with sudden death at age 13 years and (3) an ex9-14dup of the KCNH2 gene in a 12 year-old boy (QTc 550 ms) following sudden nocturnal death of his 32-year-old mother. If replicated, this study demonstrates that more than 10% of patients with LQTS and a negative current generation genetic test have large gene deletions or duplications among the major known LQTS susceptibility genes. As such, these findings suggest that sequencing-based mutation detection strategies should be followed by deletion/duplication screening in all LQTS mutation-negative patients.
Publisher: Elsevier BV
Date: 02-2015
DOI: 10.1016/J.JOCN.2014.07.023
Abstract: We present a patient with newly diagnosed Cowden syndrome and congestive myeloradiculopathy secondary to spinal dural arteriovenous fistula (SDAVF). This patient illustrates the difficulties that can be encountered in diagnosing SDAVF and emphasises the need to pursue the diagnosis in the appropriate clinical setting, as treatment can lead to significant neurological improvement. To our knowledge this is also the first reported case of an association between Cowden syndrome and SDAVF.
Publisher: Hindawi Limited
Date: 2012
DOI: 10.1155/2012/459602
Publisher: Oxford University Press (OUP)
Date: 1991
Publisher: Wiley
Date: 18-01-2011
DOI: 10.1111/J.1440-1754.2010.01948.X
Abstract: The aim of this study was to develop and apply a mutation screening protocol for the ASS1 gene in order to confirm the diagnosis of citrullinaemia type I in neonates with elevated citrulline on expanded newborn screening (E-NBS). Three patients with an elevated citrulline level were identified via routine E-NBS between January and October 2008. Analysis of the ASS1 gene using a polymerase chain reaction and sequencing-based method was successfully applied to all three patients, together with a rapid mutation-specific detection method. Their clinical progress was followed for 16-22 months. All three patients were homozygous for a previously reported missense mutation, c.787G>A (p.Val263Met), associated with a mild or asymptomatic clinical course. As a consequence of E-NBS, an increasing number of neonates with elevated citrulline of uncertain clinical significance are being identified. Rapid sequence analysis of the ASS1 gene can be used to confirm citrullinaemia type I and, increasingly, to infer phenotypic severity. Homozygosity for the same mutation was found in all three patients despite non-consanguinity and variable Pacific Island origin. These data suggest that this mutation may be relatively prevalent in these ethnic groups and imply a possible founder effect.
Publisher: Wiley
Date: 09-1990
Abstract: We have characterized deletions of the dystrophin gene in patients suffering from relatively mild muscular dystrophy. Our data show that most of the Becker muscular dystrophy (BMD) patients have intragenic deletions which leave the protein reading frame in phase. Remarkably, large deletions of the region corresponding to the central triple helical repeats in the protein can result in an exceptionally mild phenotype. Three brothers suffering from BMD, glycerol kinase deficiency, and adrenal hypoplasia possess a deletion at the 3' end of the gene. They also display developmental delay. Thus the 3' processing of the gene must be necessary for the correct function of the dystrophin molecule.
Publisher: Elsevier BV
Date: 06-1996
DOI: 10.1016/0306-4522(95)00596-X
Abstract: The cellular abundance of neuronal nitric oxide synthase and somatostatin messenger RNAs was compared in the caudate nucleus, putamen and sensorimotor cortex of Huntington's disease and control cases. Neuronal nitric oxide synthase messenger RNA was significantly decreased in the caudate nucleus and putamen, but not in the sensorimotor cortex in Huntington's disease the decrease in neuronal nitric oxide synthase messenger RNA became more pronounced with the severity of the disease. Somatostatin gene expression was significantly decreased in the dorsal putamen in Huntington's disease, but was essentially unchanged in all other regions examined. The density of neurons expressing detectable levels of neuronal nitric oxide synthase messenger RNA was reduced in the striata of Huntington's disease cases with advanced pathology the density of neurons expressing detectable levels of somatostatin messenger RNA was similar in control and Huntington's disease cases. Neuropeptide Y-, somatostatin- and NADPH-diaphorase-positive neurons were consistently present throughout the striatum across all the grades of the disease. Neuronal nitric oxide synthase and NADPH-diaphorase activity (a histochemical marker for nitric oxide synthase-containing neurons) co-localize with somatostatin and neuropeptide Y in interneurons in the human striatum and cerebral cortex. Although the neurodegeneration associated with Huntington's disease is most evident in the striatum (particularly the dorsal regions), neuronal nitric oxide synthase/neuropeptide Y/somatostatin interneurons are relatively spared. Nitric oxide released by neuronal nitric oxide synthase-containing neurons may mediate glutamate-induced excitotoxic cell death, a mechanism proposed to be instrumental in causing the neurodegeneration seen in Huntington's disease. The results described here suggest that although the population of interneurons containing somatostatin, neuropeptide Y and neuronal nitric oxide synthase do survive in the striatum in Huntington's disease they are damaged during the course of the disease. The results also show that the reduction in neuronal nitric oxide synthase and somatostatin messenger RNAs is most pronounced in the more severely affected dorsal regions of the striatum. Furthermore, the loss of neuronal nitric oxide messenger RNA becomes more pronounced with the severity of the disease thus implying a down-regulation in neuronal nitric oxide synthase messenger RNA synthesis, and potentially neuronal nitric oxide synthase protein levels, in Huntington's disease.
Publisher: Informa UK Limited
Date: 03-2007
Abstract: The zebrafish has proved to be an informative model of vertebrate development and, more recently, an emerging model of human disease. The realization of the full potential of the zebrafish as a disease model lies in two interdependent areas. The first is an appreciation that the often overlooked strength of this species lies in allowing the design of experiments that address the interplay of genetics and the environment in a manipulable manner. The second is in the application and further development of gene targeting approaches. These twin features will be addressed in this review in the context of modeling inflammatory bowel disease.
Publisher: Elsevier
Date: 2011
Publisher: Elsevier BV
Date: 11-2009
DOI: 10.1016/J.CANLET.2009.05.010
Abstract: Although activin is a major cytokine produced by the ovary, its role in epithelial ovarian cancer is poorly defined. Here, we demonstrate a novel role for activin as a growth inhibitor of some (8/16) epithelial ovarian cancer cell lines. Unresponsive cell lines displayed transcriptional downregulation of the activin receptors ACTRIIA and ACTRIB, suggesting resistance to activin signalling. In response to activin, growth inhibited cell lines demonstrated activation of the canonical SMAD2/3/4, transcriptional induction of the CDK inhibitor p15INK4B, suppression of C-MYC levels and a G1 phase cell cycle arrest. Thus, activin is a potent inhibitor of proliferation of some epithelial ovarian cancer cell lines and its role in the pathogenesis of this disease needs to be re-evaluated.
Publisher: Elsevier BV
Date: 10-1995
DOI: 10.1016/S0890-8508(95)91700-4
Abstract: Microsatellites of the dystrophin gene have been used extensively in the genetic analysis of Duchenne and Becker muscular dystrophy families. The microsatellites that have been reported to date are clustered within disparate regions of the dystrophin gene, specifically at the 5'-end and in the central rod-domain. YACs encompassing the gene were screened for further microsatellites to improve the density of available genetic markers. Four microsatellites were localized to defined regions of the dystrophin gene by the analysis of patient DNA s les, somatic cell hybrids and YACs. In addition, varying combinations of microsatellite loci were lified in multiplex PCRs, which complement those loci that have been studied to date.
Publisher: Elsevier BV
Date: 02-2014
Publisher: Hindawi Limited
Date: 2013
DOI: 10.1155/2013/823451
Abstract: We report on three patients with interstitial deletions of the long arm of chromosome 2 involving bands 2q32.1–q35. They presented with wide-ranging phenotypic variation including facial dysmorphisms, cleft palate, learning difficulties, behavioural issues and severe heart defects. Microarray analysis confirmed an 8.6 Mb deletion in patients 1 and 2 and a 24.7 Mb deletion in patient 3. We discuss the genes involved in the deleted regions including MYO1B , GLS , FRZB , SATB2 , and CPS1 and compare the phenotype with those reported in the literature. Taken together, these data suggest that there is a spectrum of disease severity such that patients with deletions encompassing the region of 2q32.1q32.2, which includes the FRZB gene, show an apparently milder phenotype compared to those that lie further distal in 2q32.3q35 that encompasses the SATB2 gene.
Publisher: Elsevier BV
Date: 2000
Publisher: China Science Publishing & Media Ltd.
Date: 05-2007
Publisher: Elsevier BV
Date: 03-2013
DOI: 10.1016/J.EJMG.2012.12.006
Abstract: The increased use of array-CGH and SNP-arrays for genetic diagnosis has led to the identification of new microdeletion/microduplication syndromes and enabled genotype-phenotype correlations to be made. In this study, nine patients with 9q21 deletions were investigated and compared with four previously Decipher reported patients. Genotype-phenotype comparisons of 13 patients revealed several common major characteristics including significant developmental delay, epilepsy, neuro-behavioural disorders and recognizable facial features including hypertelorism, feature-less philtrum, and a thin upper lip. The molecular investigation identified deletions with different breakpoints and of variable lengths, but the 750 kb smallest overlapping deleted region includes four genes. Among these genes, RORB is a strong candidate for a neurological phenotype. To our knowledge, this is the first published report of 9q21 microdeletions and our observations strongly suggest that these deletions are responsible for a new genetic syndrome characterised by mental retardation with speech delay, epilepsy, autistic behaviour and moderate facial dysmorphy.
Publisher: Medknow
Date: 2009
Abstract: While the clinical and immunocytochemical features of sarcoglycanopathies have been reported from India, genetic aspects have not been studied. There is large variation in the sarcoglycan mutations among the studied populations. To study the spectrum of mutations in sarcoglycan genes (SG). Patients fulfilling Bushby's criteria for limb girdle muscular dystrophy were prospectively analyzed. Patients gave their medical history and underwent a clinical examination, serum creatine kinase estimation, electrophysiology, muscle biopsy with immunostaining for alpha, beta, gamma, and delta subunits and mutational analysis using denaturing high pressure liquid chromatography and direct sequencing. Mutations in SG accounted for 26.4% of the cohort of limb girdle muscular dystrophy. The mean age of these 18 patients was 22.5 years. Generally, proximal weakness affected the flexor and adductor compartments of the lower and upper limbs. The clinical profile of various mutations was indistinguishable from each other. Gamma SG mutations were most common, seen in 8 patients, followed by delta SG mutation in 5 patients and alpha mutation in 4 patients, while only 1 patient had mutation in the beta sarcoglycan gene. The most prevalent mutation in the gamma SG gene was 525del T. This is of interest as the mutation has been known to exist only in specific populations. This study, the first mutational analysis of Indian patients with sarcoglycanopathies suggests gamma SG mutations were the most common and the most prevalent mutation in the gamma SG gene was 525del T.
Publisher: Oxford University Press (OUP)
Date: 1993
DOI: 10.1093/HMG/2.4.491
Publisher: Elsevier BV
Date: 10-2002
DOI: 10.1016/S0168-8227(02)00126-2
Abstract: Genetic studies suggest a diabetes susceptibility locus on human chromosome 20, near the melanocortin receptor-3 (MC3-R) gene. We examined the MC3-R as a candidate gene for type 2 diabetes in 12 members of a large Maori kindred with multiple affected members. The coding region of the MC3-R gene was sequenced for both diabetic and non-diabetic in iduals. Two separate single base pair substitutions were found in the MC3-R coding sequence and these resulted in amino acid changes, Lysine6Threonine and Isoleucine81Valine. Neither of these MC3-R variants tracked with the presence of diabetes. Furthermore, the variant and wild type MC3-R showed similar functional coupling to adenylyl cyclase. A polymorphic marker (D20S32e) close to the human MC3-R (hMC3-R) coding sequence was investigated in a 60-member pedigree for association with diabetes and other metabolic parameters. There was an association between D20S32e genotype and fasting insulin (P=0.0085) and the insulin resistance index, HOMA-R (P=0.0042). An association was also found between genotype and HDL levels during oral glucose tolerance testing (P=0.0037). These associations were independent of BMI, age, gender and diabetes. Our data do not support a role for variations in the coding region of the hMC3-R in the development of type 2 diabetes in this Maori kindred, but suggest that a locus on chromosome 20 q, close to D20S32e, may contribute to both insulin secretion and action in the Maori kindred.
Publisher: Spandidos Publications
Date: 20-03-2013
Abstract: Global developmental delay (GDD) affects ~1-3% of children, many of whom will also have intellectual disability (ID). Fragile X is the major genetic cause of GDD with mental retardation (MR) in males, accounting for ~20% of all X-linked MR. As Fragile X has serious genetic implications, the overwhelming majority of developmental delay (DD) cases referred to our laboratory are concerned with the exclusion of a diagnosis of Fragile X, along with simultaneous karyotype analysis to confirm chromosome aberrations. Critically, molecular laboratories have generally experienced a falling positive detection frequency of Fragile X. In this context, the recent implementation of array‑based techno-logy has significantly increased the likelihood of detecting chromosome aberrations that underpin DD. In the current study, we report a Fragile X mutation detection frequency for DD referrals that is comparable with the falling UK detection frequencies. In addition, we find that there is a 9‑fold greater likelihood of detecting clinically significant chromosomal aberrations than of detecting a full Fragile X mental retardation 1 (FMR1) gene CGG repeat expansion in cases referred on the basis of DD. We propose a more efficent sequential testing algorithm that involves an initial molecular karyotype, cascading to FMR1 gene analysis in the event of a negative result.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 02-2014
DOI: 10.1161/CIRCGENETICS.113.000415
Abstract: Large gene rearrangements, not detectable by standard molecular genetic sequencing techniques, are present in a minority of patients with long QT syndrome. We aimed to screen for large rearrangements in genes responsible for long QT syndrome as part of the molecular autopsy of a 36-year-old woman who died suddenly and had a negative autopsy. A retrospective analysis of an ECG identified a long QT interval, but sequencing of known LQT genes was uninformative. Array comparative genomic hybridization was used to screen for deletions and duplications in 101 genes implicated in cardiac disorders and sudden death using a postmortem blood s le. A 542 kb deletion encompassing the entire KCNJ2 gene was identified in the decedent. The mother had electrocardiographic U-wave changes consistent with Andersen–Tawil syndrome and exaggerated by exercise but none of the characteristic noncardiac features. Fluorescence in situ hybridization confirmed the deletion in the decedent and established its presence in the mother. A novel application of array comparative genomic hybridization and fluorescence in situ hybridization has identified that long QT syndrome and sudden cardiac death may occur as a result of a deletion of an entire gene. The case also supports recent research suggesting that noncardiac features of Andersen–Tawil syndrome occur only with missense or minor gene rearrangements in the KCNJ2 gene, resulting in a dominant negative effect on Kir2.x channels.
Publisher: Elsevier BV
Date: 06-2010
DOI: 10.1016/J.BBRC.2010.04.157
Abstract: Long QT syndrome is a disorder that is characterised by a prolonged QT-interval and can lead to fatal cardiac arrhythmias. Many animal models have been created to study congenital long QT syndrome. Of these, zebrafish models have involved targeting two different KCNH2 gene (long QT syndrome 2) orthologues, termed zerg-2 and zerg-3, with differing cardiac phenotypes. In order to clarify this situation, this study uses a bioinformatic approach to search the current zebrafish genome sequence (Zv7 and Zv8 builds) to investigate and locate all likely zebrafish orthologues of the human KCNH2 gene. Quantitative real-time RT-PCR was also used to determine the temporal and spatial gene expression profile of the zebrafish orthologues. The data support the conclusion that zerg-2 and zerg-3 are apparent orthologues of different human genes encoding potassium ion channels, but that their functions have switched compared to the respective human proteins.
Publisher: Wiley
Date: 21-10-2018
DOI: 10.1002/MGG3.476
Publisher: Springer Science and Business Media LLC
Date: 24-08-2021
DOI: 10.1007/S10875-021-01115-2
Abstract: Human serine/threonine kinase 4 (STK4) deficiency is a rare, autosomal recessive genetic disorder leading to combined immunodeficiency however, the extent to which immune signaling and host defense are impaired is unclear. We assessed the functional consequences of a novel, homozygous nonsense STK4 mutation (NM_006282.2:c.871C T, p.Arg291*) identified in a pediatric patient by comparing his innate and adaptive cell-mediated and humoral immune responses with those of three heterozygous relatives and unrelated controls. The genetic etiology was verified by whole genome and Sanger sequencing. STK4 gene and protein expression was measured by quantitative RT-PCR and immunoblotting, respectively. Cellular abnormalities were assessed by high-throughput RT-RCR, RNA-Seq, ELISA, and flow cytometry. Antibody responses were assessed by ELISA and phage immunoprecipitation-sequencing. The patient exhibited partial loss of STK4 expression and complete loss of STK4 function combined with recurrent viral and bacterial infections, notably persistent Epstein–Barr virus viremia and pulmonary tuberculosis. Cellular and molecular analyses revealed abnormal fractions of T cell subsets, plasmacytoid dendritic cells, and NK cells. The transcriptional responses of the patient’s whole blood and PBMC s les indicated dysregulated interferon signaling, impaired T cell immunity, and increased T cell apoptosis as well as impaired regulation of cytokine-induced adhesion and leukocyte chemotaxis genes. Nonetheless, the patient had detectable vaccine-specific antibodies and IgG responses to various pathogens, consistent with a normal CD19 + B cell fraction, albeit with a distinctive antibody repertoire, largely driven by herpes virus antigens. Patients with STK4 deficiency can exhibit broad impairment of immune function extending beyond lymphoid cells.
Publisher: Informa UK Limited
Date: 10-2009
DOI: 10.1586/EGH.09.47
Abstract: Crohn's disease (CD), a form of inflammatory bowel disease (IBD), provides a complex model of host-microbe interactions underpinning disease pathogenesis. Although there is not widespread agreement on the etiology of CD, there is evidence that microorganisms lead to the often severe inflammatory response characteristic of the disease. Despite several microbial candidates, no specific microbe has been considered pathogenic. Instead, the concept of the 'pathogenic community' has emerged from the evidence, whereby the stability of the microbial ecosystem of the healthy human gut is disrupted in response to host genetics and destabilized immunity, perhaps through changing public health practices leading to altered microbial exposures over time. We discuss the complex microbial ecosystem of the mammalian gut, the underlying genetic factors that predispose to CD, and how these gene variants may alter host-microbe interactions and propagate inflammation. Over the next 5 years, the increased understanding of genes involved in CD and the way in which in iduals with variants of these genes respond differently to nutrients and drugs will enable the rational development of personalized therapies, using pharmacogenomic and nutrigenomic approaches.
Publisher: Hindawi Limited
Date: 2012
DOI: 10.1155/2012/172408
Abstract: The contactin-associated protein-like 2 ( CNTNAP2 ) gene is highly expressed in the frontal lobe circuits in the developing human brain. Mutations in this gene have been associated with several neurodevelopmental disorders such as autism and specific language impairment. Here we describe a 450 kb deletion within the CNTNAP2 gene that is maternally inherited in two male siblings, but with a variable clinical phenotype. This variability is described in the context of a limited number of other cases reported in the literature. The in-frame intragenic deletion removes a critical domain of the CNTNAP2 protein, and this case also highlights the challenges of correlating genotype and phenotype.
Publisher: Elsevier BV
Date: 03-2011
DOI: 10.1016/J.HRTHM.2010.11.016
Abstract: Retrospective investigation of sudden unexplained death in the young (SUDY) reveals that a high proportion is due to inherited heart disease. The purpose of this study was to ascertain the diagnostic value of postmortem long QT (LQT) genetic analysis in a prospective study of SUDY victims 1-40 years old. Denaturing high-performance liquid chromatography or direct sequencing of LQT genes 1, 2, 3, 5, and 6 was performed, in a National New Zealand protocol, in SUDY victims aged 1-40 years. Over 26 months (2006-2008), DNA was stored at autopsy from 52 victims of sudden unexpected death. Further testing revealed a diagnosis in 19 cases (poisoning 4, dilated cardiomyopathy 3, myocarditis 3, other 9). The remaining 33 cases underwent genetic testing (age at death 18 months-40 years, median 25 years). Eighteen (55%) died during sleep or at rest, and 7 (21%) died during light activity. Rare missense variants in LQT genes were found in 5 (15%) cases (confidence interval 3%-27%): T96R in KCNQ1 (11-year-old male), P968L in KCNH2 (32-year-old female), P2006A in SCN5A (34-year-old female), and R67H and R98W in KCNE1 (17- and 38-year-old females, respectively). Evidence of pathogenicity was provided by in vitro evidence (T96R), family phenotype-genotype co-segregation (R98W, P2006A), and/or previous reports (R67H, P968L, P2006A, R98W). Family cardiac investigation was possible in 23 (70%) families and revealed probable cause of death for 5 (15%) other victims (confidence interval 3%-27%). Most community SUDY occurs at rest or during light activity. A diagnostic rate of 15% supports the transition of LQT genetic autopsy, combined with family investigation, into routine medical practice.
Publisher: Oxford University Press (OUP)
Date: 1993
DOI: 10.1093/HMG/2.3.241
Abstract: We have carried out genetic linkage analyses using fifteen polymorphic loci in the pericentromeric region of chromosome 10 in families with the inherited cancer syndromes multiple endocrine neoplasia (MEN) type 2A or 2B. A highly polymorphic microsatellite from the locus D10S141 in q11.2 was found to be recombinant with respect to the disease locus in two in iduals and defines a new proximal flanking marker for both MEN2A and 2B. An additional recombination provides evidence that the locus D10S94, also in q11.2, is the closet distal flanking marker for MEN2A. This localises the MEN2A gene to a small region of 10q11.2 flanked by the loci D10S141 and D10S94, which are separated by a sex-averaged genetic distance of 0.55 cM. The MEN2B gene maps to a larger region, flanked by D10S141 and RBP3.
Publisher: Wiley
Date: 20-02-2004
Publisher: Wiley
Date: 07-06-2010
DOI: 10.1111/J.1748-1716.2010.02111.X
Abstract: Congenital long QT syndrome (LQT) is a group of cardiac disorders associated with the dysfunction of cardiac ion channels. It is characterized by prolongation of the QT-interval, episodes of syncope and even sudden death. In iduals may remain asymptomatic for most of their lives while others present with severe symptoms. This heterogeneity in phenotype makes diagnosis difficult with a greater emphasis on more targeted therapy. As a means of understanding the molecular mechanisms underlying LQT syndrome, evaluating the effect of modifier genes on disease severity as well as to test new therapies, the development of model systems remains an important research tool. Mice have predominantly been the animal model of choice for cardiac arrhythmia research, but there have been varying degrees of success in recapitulating the human symptoms the mouse cardiac action potential (AP) and surface electrocardiograms exhibit major differences from those of the human heart. Against this background, the zebrafish is an emerging vertebrate disease modelling species that offers advantages in analysing LQT syndrome, not least because its cardiac AP much more closely resembles that of the human. This article highlights the use and potential of this species in LQT syndrome modelling, and as a platform for the in vivo assessment of putative disease-causing mutations in LQT genes, and of therapeutic interventions.
Publisher: Mary Ann Liebert Inc
Date: 12-2001
DOI: 10.1089/109065701753617408
Abstract: We have evaluated the usefulness of denaturing high performance liquid chromatography (dHPLC) for scanning the adenomatous polyposis coli (APC) gene for point mutations, small deletions, and insertions. Our assay consists of 28 sets of primers to lify the 15 exons of the APC gene. All PCR reactions were lified simultaneously using the same reaction conditions in a 96-well format and then analyzed by dHPLC, using empirically determined optimum temperatures for partial fragment denaturation. Previously studied DNA specimens from 47 familial adenomatous polyposis (FAP) patients were analyzed by dHPLC and all mutations were correctly identified and confirmed by sequence analysis. This approach identified a single-base substitution in exon 6 and a 2-bp insertion in exon 15 that initially had not been detected by single-strand conformational polymorphism (SSCP) analysis. A novel mutation in exon 15 of the APC gene, 2065delG (codon 689) that had previously been undetected by the protein truncation test (PTT) was also identified by dHPLC. We present our validation studies of dHPLC technology for APC gene analysis in terms of sensitivity and specificity and compare it to current standard scanning technologies including PTT, SSCP, and conformational sensitive gel electrophoresis (CSGE).
Publisher: S. Karger AG
Date: 1992
DOI: 10.1159/000133342
Abstract: Recently, an autosomal homolog of the dystrophin gene (DMDL) was identified on chromosome 6q24. As part of our analysis of the DMDL locus, we endeavoured to isolate DNA markers to further define the genetic map of this region. We have isolated and characterized two new genetic markers in the region of the DMDL locus, the RFLP D6S129 and a (CA) sub n /sub dinucleotide repeat polymorphism within the DMDL gene itself and have positioned them on the existing genetic map of chromosome 6q. These markers will be important in testing the hypothesis that the DMDL gene is the locus responsible for autosomal forms of neuromuscular disease.
Publisher: Springer Science and Business Media LLC
Date: 11-1991
DOI: 10.1007/BF00204929
Publisher: Wiley
Date: 04-2013
DOI: 10.1111/IMJ.12088
Abstract: Phaeochromocytomas and paragangliomas are rare neuroendocrine tumours that arise from the adrenal glands or paraganglia (paragangliomas) within the abdomen, thorax and neck. Although it was originally suggested that approximately 10% of these tumours were inherited, it is now recognised that up to approximately 30% of these tumours are associated with a germline mutation in one of the phaeochromocytoma araganglioma susceptibility genes. Of the 12 currently known genes predisposing to these tumours, the TMEM127 gene is one of the more recently identified and appears to be present in approximately 2% of apparently sporadic phaeochromocytomas. We report a 33-year-old man who presented with an apparently sporadic adrenal phaeochromocytoma and was identified as carrying a novel TMEM127 germline mutation, p.Gln139X. Patients harbouring a germline TMEM127 mutation most commonly present with an apparently sporadic solitary adrenal phaeochromocytoma. Testing patients who present with a phaeochromocytoma or paraganglioma for an underlying germline mutation needs to be considered in all patients due to implications for family members, but a strategy based on clinical and immunohistochemical findings would be prudent to limit costs.
Publisher: Wiley
Date: 07-2001
DOI: 10.1046/J.0962-1083.2001.01312.X
Abstract: Each summer Adélie penguins breed in large disjunct colonies on ice-free areas around the Antarctic continent. Comprising > 10 million birds, this species represents a dominant feature of the Antarctic ecosystem. The patchy distribution within a large geographical range, natal philopatry and a probable history of refugia, suggest that this species is likely to exhibit significant genetic differentiation within and among colonies. We present data from seven microsatellite DNA loci for 442 in iduals from 13 locations around the Antarctic continent. With the exception of one locus, there was no significant genic or genotypic heterogeneity across populations. Pairwise FST values were low with no value > 0.02. When all colonies were compared in a single analysis, the overall FST value was 0.0007. Moreover, assignment tests were relatively ineffective at correctly placing in iduals into their respective collection sites. These data reveal a lack of genetic differentiation between Adélie penguin colonies around the Antarctic continent, despite substantial levels of genetic variation. We consider this homogeneity in terms of the dispersal of in iduals among colonies and the size of breeding groups and discuss our results in terms of the glacial history of Antarctica.
Publisher: Hindawi Limited
Date: 2011
DOI: 10.1155/2011/898706
Abstract: This report is of a patient with pure trisomy of 15q24-qter who presents with the rare Ebstein anomaly and a previously unreported skeletal anomaly. Chromosome microarray analysis allowed high-resolution identification of the extent of the trisomy and provided a means of achieving higher-resolution breakpoint data. The phenotypic expression of unbalanced chromosomal regions is a complex phenomenon, and fine mapping of the involved region, as described here, is only a first step on the path to its full understanding. Overexpression of the LINGO-1 and CSPG4 genes has been implicated in developmental delay seen in other patients with trisomy of 15q24-qter, but our patient is currently too young to ascertain developmental progress. The genetic underpinning of Ebstein anomaly and the skeletal anomaly reported here is unclear based on our high-resolution dosage mapping.
Publisher: Springer Science and Business Media LLC
Date: 08-06-2010
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Donald Love.