ORCID Profile
0000-0002-6080-6503
Current Organisation
University of California, San Diego
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Publisher: Elsevier BV
Date: 2022
Publisher: Springer Science and Business Media LLC
Date: 11-11-2019
DOI: 10.1038/S41380-019-0558-2
Abstract: Multiplex families with a high prevalence of a psychiatric disorder are often examined to identify rare genetic variants with large effect sizes. In the present study, we analysed whether the risk for bipolar disorder (BD) in BD multiplex families is influenced by common genetic variants. Furthermore, we investigated whether this risk is conferred mainly by BD-specific risk variants or by variants also associated with the susceptibility to schizophrenia or major depression. In total, 395 in iduals from 33 Andalusian BD multiplex families (166 BD, 78 major depressive disorder, 151 unaffected) as well as 438 subjects from an independent, BD case/control cohort (161 unrelated BD, 277 unrelated controls) were analysed. Polygenic risk scores (PRS) for BD, schizophrenia (SCZ), and major depression were calculated and compared between the cohorts. Both the familial BD cases and unaffected family members had higher PRS for all three psychiatric disorders than the independent controls, with BD and SCZ being significant after correction for multiple testing, suggesting a high baseline risk for several psychiatric disorders in the families. Moreover, familial BD cases showed significantly higher BD PRS than unaffected family members and unrelated BD cases. A plausible hypothesis is that, in multiplex families with a general increase in risk for psychiatric disease, BD development is attributable to a high burden of common variants that confer a specific risk for BD. The present analyses demonstrated that common genetic risk variants for psychiatric disorders are likely to contribute to the high incidence of affective psychiatric disorders in the multiplex families. However, the PRS explained only part of the observed phenotypic variance, and rare variants might have also contributed to disease development.
Publisher: American Psychiatric Association Publishing
Date: 11-2009
Publisher: Oxford University Press (OUP)
Date: 21-06-2016
DOI: 10.1093/HMG/DDW181
Publisher: Springer Science and Business Media LLC
Date: 05-2019
Publisher: Springer Science and Business Media LLC
Date: 17-05-2021
Publisher: Frontiers Media SA
Date: 13-03-2019
Publisher: Springer Science and Business Media LLC
Date: 20-06-2017
DOI: 10.1038/TP.2017.115
Abstract: Borderline personality disorder (BOR) is determined by environmental and genetic factors, and characterized by affective instability and impulsivity, diagnostic symptoms also observed in manic phases of bipolar disorder (BIP). Up to 20% of BIP patients show comorbidity with BOR. This report describes the first case–control genome-wide association study (GWAS) of BOR, performed in one of the largest BOR patient s les worldwide. The focus of our analysis was (i) to detect genes and gene sets involved in BOR and (ii) to investigate the genetic overlap with BIP. As there is considerable genetic overlap between BIP, major depression (MDD) and schizophrenia (SCZ) and a high comorbidity of BOR and MDD, we also analyzed the genetic overlap of BOR with SCZ and MDD. GWAS, gene-based tests and gene-set analyses were performed in 998 BOR patients and 1545 controls. Linkage disequilibrium score regression was used to detect the genetic overlap between BOR and these disorders. Single marker analysis revealed no significant association after correction for multiple testing. Gene-based analysis yielded two significant genes: DPYD ( P =4.42 × 10 −7 ) and PKP4 ( P =8.67 × 10 −7 ) and gene-set analysis yielded a significant finding for exocytosis (GO:0006887, P FDR =0.019 FDR, false discovery rate). Prior studies have implicated DPYD , PKP4 and exocytosis in BIP and SCZ. The most notable finding of the present study was the genetic overlap of BOR with BIP ( r g =0.28 [ P =2.99 × 10 −3 ]), SCZ ( r g =0.34 [ P =4.37 × 10 −5 ]) and MDD ( r g =0.57 [ P =1.04 × 10 −3 ]). We believe our study is the first to demonstrate that BOR overlaps with BIP, MDD and SCZ on the genetic level. Whether this is confined to transdiagnostic clinical symptoms should be examined in future studies.
Publisher: Elsevier BV
Date: 02-2022
Publisher: Public Library of Science (PLoS)
Date: 25-01-2016
Publisher: Elsevier BV
Date: 07-2020
Publisher: American Psychiatric Association Publishing
Date: 08-2019
Publisher: Elsevier BV
Date: 12-2019
Publisher: Elsevier BV
Date: 06-2018
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 15-07-2008
DOI: 10.1161/CIRCULATIONAHA.107.709105
Abstract: Background— Chromogranin A (CHGA) triggers catecholamine secretory granule biogenesis, and its catestatin fragment inhibits catecholamine release. We approached catestatin heritability using twin pairs, coupled with genome-wide linkage, in a series of twin and sibling pairs from 2 continents. Methods and Results— Hypertensive patients had elevated CHGA coupled with reduction in catestatin, suggesting diminished conversion of precursor to catestatin. Heritability for catestatin in twins was 44% to 60%. Six hundred fifteen nuclear families yielded 870 sib pairs for linkage, with significant logarithm of odds peaks on chromosomes 4p, 4q, and 17q. Because acidification of catecholamine secretory vesicles determines CHGA trafficking and processing to catestatin, we genotyped at positional candidate ATP6N1 , bracketed by peak linkage markers on chromosome 17q, encoding a subunit of vesicular H + -translocating ATPase. The minor allele diminished CHGA secretion and processing to catestatin. The ATP6N1 variant also influenced blood pressure in 1178 in iduals with the most extreme blood pressure values in the population. In chromaffin cells, inhibition of H + -ATPase erted CHGA from regulated to constitutive secretory pathways. Conclusions— We established heritability of catestatin in twins from 2 continents. Linkage identified 3 regions contributing to catestatin, likely novel determinants of sympathochromaffin exocytosis. At 1 such positional candidate ( ATP6N1 ), variation influenced CHGA secretion and processing to catestatin, confirming the mechanism of a novel trans -QTL for sympathochromaffin activity and blood pressure.
Publisher: Springer Science and Business Media LLC
Date: 12-05-2020
Publisher: Elsevier BV
Date: 02-2015
Publisher: Springer Science and Business Media LLC
Date: 08-10-2018
DOI: 10.1038/S42003-018-0155-Y
Abstract: Psychiatric disorders are thought to have a complex genetic pathology consisting of interplay of common and rare variation. Traditionally, pedigrees are used to shed light on the latter only, while here we discuss the application of polygenic risk scores to also highlight patterns of common genetic risk. We analyze polygenic risk scores for psychiatric disorders in a large pedigree ( n ~ 260) in which 30% of family members suffer from major depressive disorder or bipolar disorder. Studying patterns of assortative mating and anticipation, it appears increased polygenic risk is contributed by affected in iduals who married into the family, resulting in an increasing genetic risk over generations. This may explain the observation of anticipation in mood disorders, whereby onset is earlier and the severity increases over the generations of a family. Joint analyses of rare and common variation may be a powerful way to understand the familial genetics of psychiatric disorders.
Publisher: Elsevier BV
Date: 07-2015
Publisher: Springer Science and Business Media LLC
Date: 03-2003
Publisher: Proceedings of the National Academy of Sciences
Date: 17-02-2015
Abstract: Bipolar disorder (BD) is a common, severe, and recurrent psychiatric disorder with no known cure and substantial morbidity and mortality. Heritable causes contribute up to 80% of the lifetime risk for BD. Common genetic variation explains ∼25% of this heritable risk. Rare genetic variants may explain additional risk. We identified contributions of rare variants to BD by sequencing the genomes of 200 in iduals from 41 families with BD. The two main findings of this study were as follows: rare risk variants for BD were enriched in genes and pathways that regulate erse aspects of neuronal excitability and most of these risk variants were noncoding with predicted regulatory functions. These results highlight specific hypotheses for future research and potential therapeutic targets.
Publisher: Springer Science and Business Media LLC
Date: 27-02-2017
DOI: 10.1038/SREP43629
Abstract: Deficits in GABAergic inhibitory neurotransmission are a reliable finding in schizophrenia (SCZ) patients. Previous studies have reported that unaffected first-degree relatives of patients with SCZ demonstrate neurophysiological abnormalities that are intermediate between probands and healthy controls. In this study, first-degree relatives of patients with SCZ and their related probands were investigated to assess frontal cortical inhibition. Long-interval cortical inhibition (LICI) was measured from the dorsolateral prefrontal cortex (DLPFC) using combined transcranial magnetic stimulation (TMS) and electroencephalography (EEG). The study presents an extended s le of 129 subjects (66 subjects have been previously reported): 19 patients with SCZ or schizoaffective disorder, 30 unaffected first-degree relatives of these SCZ patients, 13 obsessive-compulsive disorder (OCD) patients, 18 unaffected first-degree relatives of these OCD patients and 49 healthy subjects. In the DLPFC, cortical inhibition was significantly decreased in patients with SCZ compared to healthy subjects. First-degree relatives of patients with SCZ showed significantly more cortical inhibition than their SCZ probands. No differences were demonstrated between first-degree relatives of SCZ patients and healthy subjects. Taken together, these findings show that more studies are needed to establish an objective biological marker for potential diagnostic usage in severe psychiatric disorders.
Publisher: American Medical Association (AMA)
Date: 05-2019
Publisher: Springer Science and Business Media LLC
Date: 08-04-2022
Publisher: Springer Science and Business Media LLC
Date: 06-09-2019
DOI: 10.1038/S41380-019-0463-8
Abstract: Based on the discovery by the Resilience Project (Chen R. et al. Nat Biotechnol 34:531–538, 2016) of rare variants that confer resistance to Mendelian disease, and protective alleles for some complex diseases, we posited the existence of genetic variants that promote resilience to highly heritable polygenic disorders1,0 such as schizophrenia. Resilience has been traditionally viewed as a psychological construct, although our use of the term resilience refers to a different construct that directly relates to the Resilience Project, namely: heritable variation that promotes resistance to disease by reducing the penetrance of risk loci, wherein resilience and risk loci operate orthogonal to one another. In this study, we established a procedure to identify unaffected in iduals with relatively high polygenic risk for schizophrenia, and contrasted them with risk-matched schizophrenia cases to generate the first known “polygenic resilience score” that represents the additive contributions to SZ resistance by variants that are distinct from risk loci. The resilience score was derived from data compiled by the Psychiatric Genomics Consortium, and replicated in three independent s les. This work establishes a generalizable framework for finding resilience variants for any complex, heritable disorder.
Publisher: Cambridge University Press (CUP)
Date: 17-09-2018
DOI: 10.1017/S0033291718002039
Abstract: Most studies underline the contribution of heritable factors for psychiatric disorders. However, heritability estimates depend on the population under study, diagnostic instruments, and study designs that each has its inherent assumptions, strengths, and biases. We aim to test the homogeneity in heritability estimates between two powerful, and state of the art study designs for eight psychiatric disorders. We assessed heritability based on data of Swedish siblings ( N = 4 408 646 full and maternal half-siblings), and based on summary data of eight s les with measured genotypes ( N = 125 533 cases and 208 215 controls). All data were based on standard diagnostic criteria. Eight psychiatric disorders were studied: (1) alcohol dependence (AD), (2) anorexia nervosa, (3) attention deficit/hyperactivity disorder (ADHD), (4) autism spectrum disorder, (5) bipolar disorder, (6) major depressive disorder, (7) obsessive-compulsive disorder (OCD), and (8) schizophrenia. Heritability estimates from sibling data varied from 0.30 for Major Depression to 0.80 for ADHD. The estimates based on the measured genotypes were lower, ranging from 0.10 for AD to 0.28 for OCD, but were significant, and correlated positively (0.19) with national sibling-based estimates. When removing OCD from the data the correlation increased to 0.50. Given the unique character of each study design, the convergent findings for these eight psychiatric conditions suggest that heritability estimates are robust across different methods. The findings also highlight large differences in genetic and environmental influences between psychiatric disorders, providing future directions for etiological psychiatric research.
Publisher: Springer Science and Business Media LLC
Date: 28-01-2014
DOI: 10.1038/MP.2013.195
Publisher: Wiley
Date: 16-07-2015
DOI: 10.1002/AJMG.B.32344
Publisher: Elsevier BV
Date: 10-2012
Publisher: Springer Science and Business Media LLC
Date: 11-08-2202
DOI: 10.1038/NG.2711
Location: United States of America
No related grants have been discovered for Tiffany Greenwood.