A GABRA2 polymorphism improves a model for prediction of drinking initiation

作者：Kuperman Samuel^*; Chan Grace; Kramer John; Wetherill Leah; Acion Laura; Edenberg Howard J; Foroud Tatiana M; Nurnberger John Jr; Agrawal Arpana; Anokhin Andrey; Brooks Andrew; Hesselbrock Victor; Hesselbrock Michie; Schuckit Marc; Tischfield Jay; Liu Xiangtao

来源：Alcohol, 2017, 63: 1-8.

DOI：10.1016/j.alcohol.2017.03.003

• Alcohol
• Drinking initiation
• GABRA2
• rs279871
• Survival analysis modeling
• Adolescent

Background: Survival analysis was used to explore the addition of a single nucleotide polymorphism (SNP) and covariates (sex, interview age, and ancestry) on a previously published model's ability to predict onset of drinking. A SNP variant of rs279871, in the chromosome 4 gene encoding gamma-aminobutyric acid receptor (GABRA2), was selected due to its associations with alcoholism in young adults and with behaviors that increased risk for early drinking.
Methods: A subsample of 674 adolescents (ages 14-17) participating in the Collaborative Study on the Genetics of Alcoholism (COGA) was examined using a previously derived Cox proportional hazards model containing: 1) number of non-drinking related conduct disorder (CD) symptoms, 2) membership in a high-risk alcohol-dependent (AD) family, 3) most best friends drank (MBFD), 4) Achenbach Youth Self Report (YSR) externalizing score, and 5) YSR social problems score. The above covariates along with the SNP variant of GABRA2, rs279871, were added to this model. Five new prototype models were examined. The most parsimonious model was chosen based on likelihood ratio tests and model fit statistics.
Results: The final model contained four of the five original predictors (YSR social problems score was no longer significant and hence dropped from subsequent models), the three covariates, and a recessive GABRA2 rs279871 TT genotype (two copies of the high-risk allele containing thymine). The model indicated that adolescents with the high-risk TTgenotype were more likely to begin drinking than those without this genotype.
Conclusions: The joint effect of the gene (rs279871 TT genotype) and environment (MBFD) on adolescent alcohol initiation is additive, but not interactive, after controlling for behavior problems (CD and YSR externalizing score). This suggests that the impact of the high-risk TT genotype on the onset of drinking is affected by controlling for peer drinking and does not include genotype-by-environment interactions.

• 出版日期2017-9
• 单位rutgers