ORCID Profile
0000-0002-6265-3053
Current Organisation
University of New South Wales
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Publisher: Springer Science and Business Media LLC
Date: 27-06-2022
DOI: 10.1038/S41431-022-01138-2
Abstract: Duchenne muscular dystrophy (DMD), an X-linked recessive condition is maternally inherited in two-thirds of affected boys. It is important to establish carrier status of female relatives to restore reproductive confidence for non-carriers and facilitate reproductive options and cardiac surveillance for carriers. This study investigates disease incidence within an Australian model of cascade screening and evolving genetic diagnostic technologies. A retrospective population-based cohort study of all genetically and/or histopathologically confirmed males with DMD, born in New South Wales and the Australian Capital Territory was undertaken from 2002–2012. Cases were identified using state-wide molecular laboratory and clinical databases. The annual disease incidence and “theoretically” preventable cases were extrapolated over the study period. Proband genotype henotype, pedigree analysis, carrier-risk and extent of cascade screening were also determined. The cumulative incidence of disease was 19.7 per 100,000 male live births and 1 in 5076 live born males were diagnosed with DMD. Differences in disease incidence were not statistically different when compared between 2002–2007 and 2008–2012 (incidence rate ratio = 1.13, 95% CI 0.76–1.69, p = 0.52). The incidence rate ratio of theoretically preventable cases did not significantly change between 2002–2007 and 2008–2012 (incidence rate ratio = 2.07, 95% CI 0.58–9.21, p = 0.23). Current diagnostic and cascade screening models have limitations in their impact on disease incidence, due to a spectrum of logistical, patient and condition related factors. Innovative approaches to reduce DMD incidence may be better achieved by preconception or early pregnancy carrier screening, prenatal exome sequencing and newborn screening.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 12-2017
Publisher: Wiley
Date: 16-02-2022
DOI: 10.1002/ACN3.51519
Abstract: To provide a greater understanding of the tolerability, safety and clinical outcomes of onasemnogene abeparvovec in real‐world practice, in a broad population of infants with spinal muscular atrophy (SMA). A prospective cohort study of children with SMA treated with onasemnogene abeparvovec at Sydney Children's Hospital Network, Australia was conducted from August 2019 to November 2021. Safety outcomes included clinical and laboratory evaluations. Efficacy assessments included World Health Organisation (WHO) motor milestones, oral and swallowing abilities, and requirements for respiratory support. The implementation of a model of care for onasemnogene abeparvovec administration in health practice is described. 21 children were treated (age range, 0.65–24 months body weight range, 2.5–12.5 kg) and 19/21 (90.4%) had previous nusinersen. Transient treatment‐related side effects occurred in all children vomiting (100%), transaminitis (57%) and thrombocytopaenia (33%). Incidence of moderate/severe transaminitis was significantly greater in infants weighing ≥8 kg compared with kg ( p 0.05). Duration of prednisolone following treatment was prolonged (mean 87.5 days, range 57–274 days). 16/21 (76%) children gained at least one WHO motor milestone. Stabilisation or improvement in bulbar or respiratory function was observed in 20/21 (95.2%) patients. Implementation challenges were mitigated by developing standard operating procedures and facilitating exchange of knowledge. This study provides real‐world evidence to inform treatment decisions and guide therapeutic expectations for onasemnogene abeparvovec and combination therapy for SMA in health practice, especially for children weighing ≥8 kg receiving higher vector loads. Proactive clinical and laboratory surveillance is essential to facilitate in idualised management of risks.
Publisher: Springer Science and Business Media LLC
Date: 02-04-2019
Publisher: Elsevier BV
Date: 03-2021
Publisher: BMJ
Date: 26-10-2020
Abstract: To elucidate the motor unit response to intrathecal nusinersen in children with symptomatic spinal muscular atrophy (SMA) using a novel motor unit number estimation technique. MScanFit MUNE studies were sequentially undertaken from the abductor pollicis brevis muscle after stimulation of the median nerve in a prospective cohort of symptomatic children with SMA, undergoing intrathecal treatment with nusinersen at a single neuromuscular centre from June 2017 to August 2019. Electrophysiological measures included compound muscle action potential (CMAP), motor unit number estimation (MUNE), motor unit number contributing to 50%–100% of CMAP (N50) and measures of collateral reinnervation including largest single motor unit potential (LSMUP) and litude of the smallest unit contributing to N50 (A50). Twenty children (median age 99 months, range 4–193) were followed for a median of 13.8 (4–33.5) months. Therapeutic intervention was an independent and significant contributor to an increase in CMAP (p = 0.005), MUNE (p = 0.001) and N50 (p = 0.04). The magnitude of this electrophysiological response was increased in children with shorter disease durations (p .05). Electrophysiological changes delineated children who were functionally stable from those who attained clinically significant gains in motor function. Nusinersen therapy facilitated functional innervation in SMA through recovery of smaller motor units. Delineation of biomechanisms of therapeutic response may be the first step in identifying potential novel targets for disease modification in this and other motor neuropathies. MScanFit MUNE techniques may have a broader role in establishing biomarkers of therapeutic response in similar adult-onset diseases.
Publisher: Wiley
Date: 28-11-2022
DOI: 10.1111/DMCN.15117
Abstract: This study dynamically designed, evaluated, and implemented the components of an Australian newborn bloodspot screening (NBS) pilot programme for spinal muscular atrophy (SMA). We used an implementation‐effectiveness study design and continuous interdisciplinary review to measure SMA NBS test protocol performance, identify and overcome laboratory and clinical barriers to implementation, and describe progress during the 2‐year pilot study. The NBS programme screened 252 081 newborn infants from 1st August 2018 to 31st January 2021. Using an NBS pilot test protocol, 21 infants were diagnostically confirmed with SMA. The NBS pilot test protocol had a sensitivity of 100%, specificity greater than 99.9%, false‐positive rate less than 0.001%, a false‐negative rate of 0%, and positive predictive value of 95.5%. A severe phenotype was predicted on the basis of two copies of SMN2 in 57.2% of newborn infants screening positive for SMA. Clinical signs consistent with SMA were evident in 6 out of 21 screen‐positive newborn infants within the first 4 weeks of life. A multidisciplinary team establishing strong partnerships across clinical and laboratory staff was key to implementation. This pilot programme suggests that NBS is essential for early identification of newborn infants at risk of SMA and can be effectively translated into clinical practice.
Publisher: Wiley
Date: 03-12-2022
DOI: 10.1113/JP282249
Abstract: Spinal muscular atrophy (SMA) is associated with developmental disruption of motor axons in ventral roots of the spinal cord alongside motor axon degeneration. The pathogenesis of peripheral axonal change during development is pertinent to understand treatment response. Nerve excitability techniques, stimulating the median motor nerve at the wrist, were utilised to investigate axonal change during neurodevelopment in 24 children with SMA, compared with 71 age‐matched controls. Longitudinal axonal response to nusinersen treatment in 18 children was also investigated. Significant differences in axonal development were noted in the youngest children with SMA, signified by reduced compound muscle action potential (CMAP) ( P = 0.030), higher axonal threshold ( P = 0.016), rheobase (minimal current litude of infinite duration, required to generate an action potential) ( P = 0.012) and greater changes in depolarising and hyperpolarising threshold electrotonus. Subexcitability increased in all children with SMA, compared to controls. With treatment, nerve excitability changes were observed prominently in young children, with increases in CMAP, reduction in axonal threshold, fanning‐in of threshold electrotonus, increase in resting current–threshold slope and reduction in subexcitability. Whilst motor axons continue to mature in SMA, developmental delays in passive and active membrane properties occur especially in early childhood. Concurrently, motor axons actively undergo degeneration. Nusinersen restores the developmental trajectory of motor axons reducing degeneration, especially in children with early treatment initiation. Our findings move the field forward in understanding the developmental aspect of childhood‐onset motor neurone diseases and changes in axonal function associated with disease modification. Pathomechanisms in spinal muscular atrophy involve concurrent neurodevelopmental and neurodegenerative processes. The greatest delays in maturation of the passive and active properties of the peripheral motor axon are seen in early childhood. Nusinersen facilitates developmental recovery of the motor axon whilst also reducing neurodegeneration. Axonal dysfunction is reversed with SMN repletion particularly when intervention occurs early in development.
Publisher: S. Karger AG
Date: 2014
DOI: 10.1159/000360535
Abstract: b i Introduction: /i /b Extremes of fetal growth are associated with increased perinatal mortality and morbidity and a higher prevalence of cardiovascular disease, obesity and diabetes in later life. We aimed to identify changes in placental gene expression in pregnancies with evidence of growth dysfunction and candidate genes that may be used to identify abnormal patterns of growth prior to delivery. b i Methods: /i /b Growth-restricted (n = 4), macrosomic (n = 6) and normal term (n = 5) placentas were selected from a banked series (n = 200) collected immediately after caesarean section. RNA was extracted prior to microarray analysis using Affymetrix HG-U219 arrays to determine variation in gene expression. Genes of interest were confirmed using qRT-PCR. b i Results: /i /b 338 genes in the growth-restricted and 41 genes in the macrosomic group were identified to be significantly dysregulated ( -fold change p 0.05). i CPXM2 /i and i CLDN1 /i were upregulated and i TXNDC5 /i and i LRP2 /i downregulated in fetal growth restriction. In macrosomia, i PHLDB2 /i and i CLDN1 /i were upregulated and i LEP /i and i GCH1 /i were downregulated. b i Discussion: /i /b Dysfunctional growth is associated with differential placental gene expression and affects genes with a whole spectrum of developmental and cellular functions. Better elucidation of these pathways may allow the development of biomarkers to identify growth abnormalities and effective prenatal intervention.
Publisher: Frontiers Media SA
Date: 19-08-2019
Publisher: Elsevier BV
Date: 06-2021
DOI: 10.1016/J.CLNU.2021.01.013
Abstract: Little is currently known about the nutrition and growth outcomes in children with neuromuscular disorders (NMDs), and these are likely disease dependent. The aim of this study was to describe the range of nutritional issues in pediatric NMDs and identify similarities and differences in growth outcomes and nutritional needs in children with a variety of NMDs at different ages, with the goal of informing future services. In this cross-sectional study we collected data on growth, dietetic interventions and nutrition-related issues in 160 children who attended a multidisciplinary clinic in a tertiary children's hospital, from February to December 2019. Children with significant weakness affecting mobility before the age of 3 years were clinically grouped into 'early-onset NMDs'. Across our clinic, 42.5% children had a history of chronic gastrointestinal issues, and 34.4% received dietetic care on the day of clinical visit. Children with early-onset NMDs had significantly higher prevalence of swallowing issues, gastroesophageal reflux, and vomiting, as well as higher frequency of dietetic consultations, high energy diet, swallowing assessment and tube-feeding, compared to later-onset NMDs (p < 0.05). In total, 49.2% children with NMDs had an abnormal weight, in which the prevalence of underweight (n = 24, 19.2%) was significantly higher compared to normal Australian children (8.2%) (p < 0.05). In Duchenne muscular dystrophy, over 50% children were overweight/obese. Among children with NMDs, there were many disease-specific nutrition-related symptoms, growth issues, and dietetic practices that were tailored to in idual needs. Future studies should focus on measuring the impact of specific dietetic practices on growth and nutritional outcomes, as well as developing a precision medicine approach tailored to the in idual nutritional needs of children with NMDs.
Publisher: S. Karger AG
Date: 2020
DOI: 10.1159/000504975
Abstract: b i Background: /i /b Spontaneous preterm birth is the leading cause of perinatal morbidity and mortality worldwide and continues to present a major clinical dilemma. We previously reported that a number of protein species were dysregulated in maternal serum collected at 11–13 sup +6 /sup weeks’ gestation from pregnancies that continued to labour spontaneously and deliver preterm. b i Objectives and Methods: /i /b In this study, we aimed to validate changes seen in 4 candidate protein species: alpha-1-antitrypsin, vitamin D-binding protein (VDBP), alpha-1beta-glycoprotein and apolipoprotein A-1 in a larger cohort of women using a western blot approach. b i Results: /i /b Serum levels of all 4 proteins were reduced in women who laboured spontaneously and delivered preterm. This reduction was significant for VDBP ( i /i = 0.04), which has been shown to be involved in a plethora of essential biological functions, including actin scavenging, fatty acid transport, macrophage activation and chemotaxis. b i Conclusions: /i /b The decrease in select proteoforms of VDBP may result in an imbalance in the optimal intrauterine environment for the developing foetus as well as to a successful uncomplicated pregnancy. Thus, certain (phosphorylated) species of VDBP may be of value in developing a targeted approach to the early prediction of spontaneous preterm labour. Importantly, this study raises the importance of a focus on proteoforms and the need for any biomarker validation process to most effectively take these into account rather than the more widespread practice of simply focussing on the primary amino acid sequence of a protein.
Publisher: Elsevier BV
Date: 09-2021
Publisher: Wiley
Date: 13-08-2020
DOI: 10.1002/MUS.27030
Publisher: Elsevier BV
Date: 04-2018
DOI: 10.1016/J.JPROT.2018.02.002
Abstract: Spontaneous preterm birth (sPTB) remains a major clinical dilemma current diagnostics and interventions have not reduced the rate of this serious healthcare burden. This study characterizes differential protein profiles and post-translational modifications (PTMs) in first trimester maternal serum using a refined top-down approach coupling two-dimensional gel electrophoresis (2DE) and mass spectrometry (MS) to directly compare subsequent term and preterm labour events and identify marked protein differences. 30 proteoforms were found to be significantly increased or decreased in the sPTB group including 9 phosphoproteins and 11 glycoproteins. Changes occurred in proteins associated with immune and defence responses. We identified protein species that are associated with several clinically relevant biological processes, including interrelated biological networks linked to regulation of the complement cascade and coagulation pathways, immune modulation, metabolic processes and cell signalling. The finding of altered proteoforms in maternal serum from pregnancies that delivered preterm suggests these as potential early biomarkers of sPTB and also possible mediators of the disorder. Identifying changes in protein profiles is critical in the study of cell biology, and disease treatment and prevention. Identifying consistent changes in the maternal serum proteome during early pregnancy, including specific protein PTMs (e.g. phosphorylation, glycosylation), is likely to provide better opportunities for prediction, intervention and prevention of preterm birth. This is the first study to examine first trimester maternal serum using a highly refined top-down proteomic analytical approach based on high resolution 2DE coupled with mass spectrometry to directly compare preterm (<37 weeks) and preterm (≥37 weeks) events and identify select protein differences between these conditions. As such, the data present a promising avenue for translation of biomarker discovery to a clinical setting as well as for future investigation of underlying aetiological processes.
Publisher: MDPI AG
Date: 06-06-2017
Publisher: Springer Science and Business Media LLC
Date: 12-03-2020
DOI: 10.1186/S13023-020-1339-3
Abstract: Spinal muscular atrophy (SMA) is a neurodegenerative disease that has a substantial and multifaceted burden on affected adults. While advances in supportive care and therapies are rapidly reshaping the therapeutic environment, these efforts have largely centered on pediatric populations. Understanding the natural history, care pathways, and patient-reported outcomes associated with SMA in adulthood is critical to advancing health policy, practice and research across the disease spectrum. The aim of this study was to systematically review research investigating the healthcare, well-being and lived experiences of adults with SMA. In accordance with the Preferred Reported Items for Systematic Reviews and Meta-Analysis guidelines, seven electronic databases were systematically searched until January 2020 for studies examining clinical (physical health, natural history, treatment) and patient-reported (symptoms, physical function, mental health, quality of life, lived experiences) outcomes in adults with SMA. Study risk of bias and the level of evidence were assessed using validated tools. Ninety-five articles met eligibility criteria with clinical and methodological ersity observed across studies. A heterogeneous clinical spectrum with variability in natural history was evident in adults, yet slow declines in motor function were reported when observational periods extended beyond 2 years. There remains no high quality evidence of an efficacious drug treatment for adults. Limitations in mobility and daily activities associated with deteriorating physical health were commonly reported, alongside emotional difficulties, fatigue and a perceived lack of societal support, however there was no evidence regarding effective interventions. This systematic review identifies the many uncertainties regarding best clinical practice, treatment response, and long-term outcomes for adults with SMA. This comprehensive identification of the current gaps in knowledge is essential to guide future clinical research, best practice care, and advance health policy with the ultimate aim of reducing the burden associated with adult SMA.
No related grants have been discovered for Arlene D'Silva.