Evidence for genetic linkage to alcohol dependence on chromosomes 4 and 11 from an autosome-wide scan in an American Indian population

To identify specific genes affecting vulnerability or resistance, we performed a whole-autosomal genome scan for genetic linkage to alcohol dependence in a Southwestern American Indian tribe. Genotypes at 517 autosomal microsatellite loci and clinical evaluations were available for 152 subjects belonging to extended pedigrees and forming 172 sib-pairs. Highly suggestive evidence for linkage emerged for two genomic regions using two- and multipoint sib-pair regression methods; both regions harbored neurogenetic candidate genes. The best evidence is seen with D11S1984 (nominal P = 0.00007, lod ≃ 3.1) on chromosome 11p, in close proximity to the DRD4 dopamine receptor and tyrosine hydroxylase (TH) genes. Good evidence is seen with D4S3242 (nominal P = 0.0002, lod ≃ 2.8) on chromosome 4p, near the β1 GABA receptor gene. Interestingly, three loci in the alcohol dehydrogenase gene cluster on chromosome 4q showed evidence for linkage with two-point analyses, but not multipoint analysis.