GABA(A) receptor subunit genes clustered on 5q33 play a role in the development of alcoholism and methamphetamine use disorder without psychosis. The present study explored the possible contribution of the same subunit genes to the development of heroin dependence. Single nucleotide polymorphisms (SNPs) of the GABAA receptor subunits GABRB2, GABRA6, GABRA1, and GABRG2 were examined in 178 male Han Chinese heroin-dependent and 170 male control subjects. A significant difference in allele frequency for the SNP rs211014 in the GABA(A)gamma 2 receptor subunit gene between cases and controls was identified (P=0.015). A possible mechanism for the involvement of the GABA receptor subunit genes on 5q33 in the development of heroin dependence is discussed. (c) 2007 Wiley-Liss, Inc.
