A recent preliminary genome-wide association study (GWAS) of male sexual orientation presented in Scientific Reports this week suggests genes may have play apart in sexual orientation in men but says connections are at best “speculative”.
While a man’s sexual orientation is multifactorial, with evidence of multiple genetic and environmental contributions, nature versus nurture. However, genetic association studies for men’s sexual orientation have been sparse.
Alan Sanders and colleagues conducted a GWAS of male sexual orientation involving 1,077 homosexual men and 1,231 heterosexual men, primarily of European ancestry.
The authors detected several regions with multiple single nucleotide polymorphisms (single-letter changes in the DNA), the most prominent of which were located on chromosomes 13 and 14 near genes that have functions plausibly relevant to the genes for development of sexual orientation.
Dr Nina McCarthy, a Research Fellow in the Centre for Genetic Origins of Health and Disease at the University of Western Australia says”We know from family studies that genes may play a role in male sexual orientation; however which genes specifically may be involved has not been well studied. This paper reports the first published study which has examined genetic variants across the whole genome for association with homosexuality in European men. As this study was carried out in European men, we do not know whether the findings will apply to homosexuality in women, or even to homosexuality in non-European men.”