A quantitative-trait genome-wide association study of alcoholism risk in the community: findings and implications

Biol Psychiatry. 2011 Sep 15;70(6):513-8. doi: 10.1016/j.biopsych.2011.02.028. Epub 2011 May 6.

Abstract

Background: Given moderately strong genetic contributions to variation in alcoholism and heaviness of drinking (50% to 60% heritability) with high correlation of genetic influences, we have conducted a quantitative trait genome-wide association study (GWAS) for phenotypes related to alcohol use and dependence.

Methods: Diagnostic interview and blood/buccal samples were obtained from sibships ascertained through the Australian Twin Registry. Genome-wide single nucleotide polymorphism (SNP) genotyping was performed with 8754 individuals (2062 alcohol-dependent cases) selected for informativeness for alcohol use disorder and associated quantitative traits. Family-based association tests were performed for alcohol dependence, dependence factor score, and heaviness of drinking factor score, with confirmatory case-population control comparisons using an unassessed population control series of 3393 Australians with genome-wide SNP data.

Results: No findings reached genome-wide significance (p = 8.4 × 10(-8) for this study), with lowest p value for primary phenotypes of 1.2 × 10(-7). Convergent findings for quantitative consumption and diagnostic and quantitative dependence measures suggest possible roles for a transmembrane protein gene (TMEM108) and for ANKS1A. The major finding, however, was small effect sizes estimated for individual SNPs, suggesting that hundreds of genetic variants make modest contributions (1/4% of variance or less) to alcohol dependence risk.

Conclusions: We conclude that 1) meta-analyses of consumption data may contribute usefully to gene discovery; 2) translation of human alcoholism GWAS results to drug discovery or clinically useful prediction of risk will be challenging; and 3) through accumulation across studies, GWAS data may become valuable for improved genetic risk differentiation in research in biological psychiatry (e.g., prospective high-risk or resilience studies).

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alcohol Drinking / genetics*
  • Alcoholism / diagnosis
  • Alcoholism / genetics*
  • Case-Control Studies
  • Genetic Predisposition to Disease / genetics*
  • Genome-Wide Association Study / statistics & numerical data*
  • Genotype
  • Humans
  • Phenotype
  • Polymorphism, Single Nucleotide
  • Quantitative Trait Loci / genetics*
  • Residence Characteristics