
 Excessive alcohol consumption contributes to significant morbidity and  mortality. Heritable influences contribute to 50% of the variation in alcohol  consumption, suggesting the important role of genes. 
We used data on a previously defined alcohol consumption factor score in a sample of 827 young women to investigate association with 1,014 single-nucleotide polymorphisms in genes related to addiction.
We used data on a previously defined alcohol consumption factor score in a sample of 827 young women to investigate association with 1,014 single-nucleotide polymorphisms in genes related to addiction.
Data were drawn from the Missouri Adolescent Female Twin  Study (MOAFTS) with replication in the college drinking sample (CDS). Genotypic  and phenotypic data were available on 827 MOAFTS and 100 CDS women of  European-American ancestry. Data on 1,014 single-nucleotide polymorphisms (SNPs)  across 130 genes related to addiction were utilized. Association was conducted  in QTDT, which allows for identity-by-descent information to account accurately  for twin status in the analysis. The total association variance components model  was used, with specification of variance components for relatedness in  MOAFTS.
The top signals included clusters of SNPs in tryptophan  hydroxylase 2 (TPH2) (e.g., rs1386496, p = 0.0003) and dopa  decarboxylase (DDC) (e.g., rs3779084, p = 0.0008), genes that  encode proteins responsible for serotonin synthesis. Additional polymorphisms in  ADH1B, ADH1C, ADH7, and ADH1A1 were also associated at  p < 0.05. The false discovery rate for the top signal  (p = 0.0003) was 0.15, suggesting nominal significance only.  Replication was limited and noted for 2 SNPs in ADH1C.
While no results survive the burden of multiple testing,  nominal findings in TPH2 and DDC suggest the potential role of  the serotonin synthesis pathway in alcohol consumption.
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Request Reprint E-Mail: arpana@wustl.edu
 
