But experts say the origins of partner preference remain a mystery. For men, new research suggests that clues to sexual orientation may lie not just in the genes, but in the spaces between the DNA, where molecular marks instruct genes when to turn on and off and how strongly to express themselves. That news, presented at the meeting of the American Society of Human Genetics on Thursday, may leave the genetically uninitiated scratching their heads. Through the epigenome, the results suggest, some facet of life experience likely also primes a man for same-sex attraction. But they increasingly suspect it is forged, in part, by the stresses and demands of external influences.
You’re born gay or straight, sexuality is written in a man’s DNA, scientists believe
Gay gene research could trace the queer family tree, but should it?
But geneticists have had only a handful of underpowered studies to address a complex, fraught, and often stigmatized area of human behavior. Now, the largest-ever study of the genetics of sexual orientation has revealed four genetic variants strongly associated with what the researchers call nonheterosexual behavior. Some geneticists are hailing the findings as a cautious but significant step in understanding the role of genes in sexuality. Others question the wisdom of asking the question in the first place. Andrea Ganna, a research fellow with the Broad Institute in Cambridge, Massachusetts, and Harvard Medical School in Boston, and colleagues examined data from hundreds of thousands of people who provided both DNA and behavioral information to two large genetic surveys, the UK Biobank study and the private genetics firm 23andMe. The researchers performed a genome-wide association study GWAS in which they looked for specific variations in DNA that were more common in people who reported at least one same-sex sexual experience.
Giant study links DNA variants to same-sex behavior
Please refresh the page and retry. G enes linked to homosexuality have been discovered by scientists in the biggest ever study into the genetic basis for sexual orientation. SLITRK6 is an important gene for brain development, and is particularly active in a region of the brain which includes the hypothalamus.
Reuters - U. Findings from the study, which has yet to be published or reviewed in detail by other scientists, were presented at a meeting of the American Society of Human Genetics in Baltimore. It followed 37 pairs of identical male twins in which one was homosexual and one heterosexual, and 10 sets of twins in which both males were homosexual.