Association of CHRM2 polymorphisms with severity of alcohol dependence.

The cholinergic muscarinic 2 receptor (CHRM2) gene has been considered a candidate gene for the alcohol dependence in that it might underpin certain risk factors for this condition. This study examined variations in the CHRM2 between the patients with alcohol dependence and population controls in Korean and explored the associations between CHRM2 polymorphisms and severity of symptoms in the patients with alcohol dependence. One hundred and fifty-five patients with alcohol dependence, defined by the Alcohol Use Disorders Identification Test (AUDIT) and the Alcohol Dependence Scale (ADS) to measure the severity of symptoms, and one hundred and ninety-five population controls were drawn in the study. Three single nucleotide polymorphisms (SNPs) of CHRM2 were genotyped using the TaqMan assay and analyzed with the severity of symptoms of alcohol dependence. We found that although SNP rs324650 showed marginal association with the risk of alcohol dependence (P = 0.03), the significance of the result was not sustained after multiple corrections. SNP rs1824024 was significantly associated with the AUDIT and ADS scores in patients (P = 0.005 and 0.003, respectively). These findings suggested that the muscarinic acetylcholine function might be related not with alcohol dependence itself but with the severity of alcohol dependence in Korean population.