[Association studies of dopamine D4 receptor gene exon 3 in patients with alcohol dependence].

AIM The aim of this study was to evaluate the role of dopamine D4 receptor (DRD4) exon 3 polymorphisms (48 bp VNTR) in the pathogenesis of alcoholism. This polymorphism was investigated in the association study in a whole group of alcoholics (n = 122) and in homogenous overlapping subgroups: 1) with early age of onset of alcoholism (AOO < or = 26 years) (n = 65) and 2) with a co-occurrence of dissocial personality disorder (n = 38), and 3) in patients with a history of delirium tremens and/or alcohol seizures (n = 41). The control group consisted of healthy volunteers, gender and age matched, with excluded psychiatric disorders (n = 399). METHOD The history of alcoholism was investigated using SSAGA (Semi-Structured Assessment for the Genetics of Alcoholism - Polish version). The DRD4 receptor exon 3 polymorphism was determined using PCR. RESULTS We found significant differences in the short alleles (2-5 VNTR) frequencies between controls and patients with a history of delirium tremens and/or alcohol seizures (p = 0.043). A trend was also observed in the higher frequency of short alleles amongst individuals with an early age of onset of alcoholism (p = 0.063). CONCLUSION The results of this study suggest that inherited short variants of DRD4 alleles may play role in pathogenesis of alcohol dependence.