RESUMO
We report a genome-wide association study (GWAS) for cocaine dependence (CD) in three sets of African- and European-American subjects (AAs and EAs, respectively) to identify pathways, genes and alleles important in CD risk. The discovery GWAS data set (n=5697 subjects) was genotyped using the Illumina OmniQuad microarray (8 90 000 analyzed single-nucleotide polymorphisms (SNPs)). Additional genotypes were imputed based on the 1000 Genomes reference panel. Top-ranked findings were evaluated by incorporating information from publicly available GWAS data from 4063 subjects. Then, the most significant GWAS SNPs were genotyped in 2549 independent subjects. We observed one genome-wide-significant (GWS) result: rs2629540 at the FAM53B ('family with sequence similarity 53, member B') locus. This was supported in both AAs and EAs; P-value (meta-analysis of all samples)=4.28 × 10(-8). The gene maps to the same chromosomal region as the maximum peak we observed in a previous linkage study. NCOR2 (nuclear receptor corepressor 2) SNP rs150954431 was associated with P=1.19 × 10(-9) in the EA discovery sample. SNP rs2456778, which maps to CDK1 ('cyclin-dependent kinase 1'), was associated with cocaine-induced paranoia in AAs in the discovery sample only (P=4.68 × 10(-8)). This is the first study to identify risk variants for CD using GWAS. Our results implicate novel risk loci and provide insights into potential therapeutic and prevention strategies.
Assuntos
Negro ou Afro-Americano/genética , Transtornos Relacionados ao Uso de Cocaína/genética , Polimorfismo de Nucleotídeo Único , População Branca/genética , Adulto , Proteína Quinase CDC2 , Cocaína/efeitos adversos , Quinases Ciclina-Dependentes/genética , Inibidores da Captação de Dopamina/efeitos adversos , Feminino , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Técnicas de Genotipagem , Humanos , Masculino , Correpressor 2 de Receptor Nuclear/genética , Transtornos Paranoides/induzido quimicamente , Transtornos Paranoides/genética , Estados UnidosRESUMO
We report a GWAS of alcohol dependence (AD) in European-American (EA) and African-American (AA) populations, with replication in independent samples of EAs, AAs and Germans. Our sample for discovery and replication was 16 087 subjects, the largest sample for AD GWAS to date. Numerous genome-wide significant (GWS) associations were identified, many novel. Most associations were population specific, but in several cases were GWS in EAs and AAs for different SNPs at the same locus,showing biological convergence across populations. We confirmed well-known risk loci mapped to alcohol-metabolizing enzyme genes, notably ADH1B (EAs: Arg48His, P=1.17 × 10(-31); AAs: Arg369Cys, P=6.33 × 10(-17)) and ADH1C in AAs (Thr151Thr, P=4.94 × 10(-10)), and identified novel risk loci mapping to the ADH gene cluster on chromosome 4 and extending centromerically beyond it to include GWS associations at LOC100507053 in AAs (P=2.63 × 10(-11)), PDLIM5 in EAs (P=2.01 × 10(-8)), and METAP in AAs (P=3.35 × 10(-8)). We also identified a novel GWS association (1.17 × 10(-10)) mapped to chromosome 2 at rs1437396, between MTIF2 and CCDC88A, across all of the EA and AA cohorts, with supportive gene expression evidence, and population-specific GWS for markers on chromosomes 5, 9 and 19. Several of the novel associations implicate direct involvement of, or interaction with, genes previously identified as schizophrenia risk loci. Confirmation of known AD risk loci supports the overall validity of the study; the novel loci are worthy of genetic and biological follow-up. The findings support a convergence of risk genes (but not necessarily risk alleles) between populations, and, to a lesser extent, between psychiatric traits.
