Browsing by Subject "heritability"

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    Genome-wide association study identifies loci associated with liability to alcohol and drug dependence that is associated with variability in reward-related ventral striatum activity in African- and European-Americans
    (Wiley, 2019-05-19) Wetherill, Leah; Lai, Dongbing; Johnson, Emma C.; Anokhin, Andrey; Bauer, Lance; Bucholz, Kathleen K.; Dick, Danielle M.; Hariri, Ahmad R.; Hesselbrock, Victor; Kamarajan, Chella; Kramer, John; Kuperman, Samuel; Meyers, Jacquelyn L.; Nurnberger, John I.; Schuckit, Marc; Scott, Denise M.; Taylor, Robert E.; Tischfield, Jay; Porjesz, Bernice; Goate, Alison M.; Edenberg, Howard J.; Foroud, Tatiana; Bogdan, Ryan; Agrawal, Arpana; Medical and Molecular Genetics, School of Medicine
    Genetic influences on alcohol and drug dependence partially overlap, however specific loci underlying this overlap remain unclear. We conducted a genome-wide association study (GWAS) of a phenotype representing alcohol or illicit drug dependence (ANYDEP) among 7,291 European-Americans (EA; 2,927 cases) and 3,132 African-Americans (AA: 1,315 cases) participating in the family-based Collaborative Study on the Genetics of Alcoholism. ANYDEP was heritable (h2 in EA=0.60, AA=0.37). The AA GWAS identified 3 regions with genome-wide significant (GWS; p<5E-08) single nucleotide polymorphisms (SNPs) on chromosomes 3 (rs34066662, rs58801820) and 13 (rs75168521, rs78886294), and an insertion-deletion on chromosome 5 (chr5:141988181). No polymorphisms reached GWS in the EA. One GWS region (chromosome 1: rs1890881) emerged from a trans-ancestral meta-analysis (EA+AA) of ANYDEP, and was attributable to alcohol dependence in both samples. Four genes (AA: CRKL, DZIP3, SBK3; EA: P2RX6) and 4 sets of genes were significantly enriched within biological pathways for hemostasis and signal transduction. GWS signals did not replicate in two independent samples but there was weak evidence for association between rs1890881 and alcohol intake in the UK Biobank. Among 118 AA and 481 EA individuals from the Duke Neurogenetics Study, rs75168521 and rs1890881 genotypes were associated with variability in reward-related ventral striatum activation. This study identified novel loci for substance dependence and provides preliminary evidence that these variants are also associated with individual differences in neural reward reactivity. Gene discovery efforts in non-European samples with distinct patterns of substance use may lead to the identification of novel ancestry-specific genetic markers of risk.
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    Psychiatric genetics and the structure of psychopathology
    (Nature, 2018-01) Smoller, Jordan W.; Andreassen, Ole A.; Edenberg, Howard J.; Faraone, Stephen V.; Glatt, Stephen J.; Kendler, Kenneth S.; Biochemistry and Molecular Biology, School of Medicine
    For over a century, psychiatric disorders have been defined by expert opinion and clinical observation. The modern DSM has relied on a consensus of experts to define categorical syndromes based on clusters of symptoms and signs, and, to some extent, external validators, such as longitudinal course and response to treatment. In the absence of an established etiology, psychiatry has struggled to validate these descriptive syndromes, and to define the boundaries between disorders and between normal and pathologic variation. Recent advances in genomic research, coupled with large-scale collaborative efforts like the Psychiatric Genomics Consortium, have identified hundreds of common and rare genetic variations that contribute to a range of neuropsychiatric disorders. At the same time, they have begun to address deeper questions about the structure and classification of mental disorders: To what extent do genetic findings support or challenge our clinical nosology? Are there genetic boundaries between psychiatric and neurologic illness? Do the data support a boundary between disorder and normal variation? Is it possible to envision a nosology based on genetically informed disease mechanisms? This review provides an overview of conceptual issues and genetic findings that bear on the relationships among and boundaries between psychiatric disorders and other conditions. We highlight implications for the evolving classification of psychopathology and the challenges for clinical translation.