Association analysis between the tag SNP for sonic hedgehog rs9333613 polymorphism and male sexual orientation.

Male sexual orientation has been proposed to have genetic components, but previously suggested candidate genes have all received negative results. The human sonic hedgehog (SHH) gene is located in the 7q36 region, which was linked to male sexual orientation in a previous genome-wide association study. SHH is known to play an important role in embryo patterning, and there is evidence connecting it to sexual orientation. In this study, we performed an association analysis of the SHH tag single nucleotide polymorphism rs9333613 in 361 subjects and 319 Chinese male controls. We find a significant difference in genotype and allele distribution between identified homosexuals and heterosexual control subjects, suggesting that the SHH gene could potentially be associated with male sexual orientation.