Twin study shows distinct patterns of markers along stretches of the genome
BALTIMORE — Molecular tests may be able to distinguish homosexual from heterosexual men, a small study of twins suggests.
Chemical modifications to DNA that change the activity of genes without changing the genes’ information differ between homosexual and heterosexual men, researchers from UCLA David Geffen School of Medicine have discovered. Results of the unpublished study on the link between these modifications, called epigenetic tags, and sexual orientation were presented October 8 at the annual meeting of the American Society of Human Genetics. Comparing one type of epigenetic tag known as DNA methylation in pairs of twins in which one brother is gay and the other straight revealed patterns that distinguish one group from the other about 67 percent of the time, computational geneticist Tuck Ngun and colleagues say.