Lesch's typology differentiates alcoholics into different treatment response subgroups. The effects of ethanol are mediated, to an important extent, via the GABA-ergic system. We have evaluated the linkage disequilibrium patterns and haplotype frequencies of GABRG1 and GABRA2 genes in 133 alcoholics divided according to Lesch's typology and in 145 matched controls. Besides several relationships at a threshold of statistical significance, we found no significant differences in the haplotype distribution of these genes between alcoholics and controls. Lesch's typology may not be related with the genotype of alcoholics – at least in terms of genes with an established role in the development of dependency
