Association study of dopamine D2, D4 receptor gene, GABAA receptor beta subunit gene, serotonin transporter gene polymorphism with children of alcoholics in Korea: a preliminary study

Abstract

The studies on the genetic risk factors of the children of alcoholics (COAs) are still in an early stage. The A1 allele of the dopamine receptor 2 gene (DRD2) may be associated with positive alcohol expectancy of the COAs. In addition, several researchers reported that the COAs might be associated with the GABA A receptor beta3 subunit gene (GABRB3) and serotonin transporter gene (5-HTTLPR). In this study, we investigated the association of the polymorphism of the DRD2, Dopamine D4 receptor gene (DRD4), GABRB3, 5-HTTLPR with the COAs. Twenty-two COAs and 23 age and sex-matched control children were included for the genetic study (children of nonAlcoholics; nonCOAs). All COAs aged 6-18 were recruited and selected from family of alcoholic patients in Alcohol Clinic of the University hospital. The genotyping of the DRD2, DRD4, GABRB3, 5-HTTLPR was carried out. We used the Chi-square method for evaluating the association of genetic polymorphic allelic status with the COAs. The frequency of the A1+ allele at DRD2 in the COAs was significantly higher than nonCOAs. Significant association between the genotype at DRD4 and the COAs was found. The G1- alleles of the GABRB3 in COAs were significantly higher than nonCOAs. However, no association of the polymorphic alleles of the 5-HTTLPR with the COAs was found. We found that the children of alcoholics had a significantly increased number of risk alleles of candidate genes of alcohol drinking expectancy. Despite of several limitations, this study provides some preliminary information on the risk and protective factors associated with the COAs, which can be used as a foundation for prevention and intervention of future psychopathology.