Norepinephrine transporter polymorphisms T-182C and G1287A are not associated with alcohol dependence and its clinical subgroups

Several studies have suggested that the norepinephrine transporter (NET) may play an important role in the pathogenesis of alcohol dependence. Additional studies have shown that the polymorphisms of T-182C (rs2242446) and G1287A (rs5569) in NET gene (hSLC6A2) may affect the NET function. Therefore, in this study, we examined whether these hSLC6A2 gene polymorphisms are a susceptibility factor for alcohol dependence or its clinical subgroup(s). A total of 690 Han Chinese subjects (408 alcohol dependent patients and 282 controls) in Taiwan were recruited for this study. Individuals with alcohol dependence were classified into several clinical subgroups to reduce the clinical heterogeneity. All subjects were interviewed with identical methods, and the mental disorders were diagnosed according to DSM-IV criteria. The polymorphisms of T-182C and G1287A in hSLC6A2 gene were analyzed by using a standard method. No significant differences in genotype and allele frequencies of hSLC6A2 polymorphisms were found between controls and total alcohol dependence or between more homogeneous subgroups with alcohol dependence and controls. This study suggests that the polymorphisms of T-182C and G1287A in hSLC6A2 gene are not major risk factors in increasing susceptibility to either alcohol dependence or its clinical subtypes.