Updated on September 6th, 2018
The study, out of the NorthShore University HealthSystem’s Research Institute, notes that there is some precedent for a genetic focus — previous studies of families and twins suggest that genes play a role in sexual orientation.
Building on this foundation, a new large-scale genetic study explores the roots of male sexual orientation, finding two regions of genetic variance in homosexual men.Looking at the genomes of 1,077 self-identified homosexual men and 1,231 self-identified heterosexual men, the researchers found two regions that seemed to be significant.
The first, on chromosome 13, was a region near a gene called SLITRK6. This gene is involved in brain development and is mostly expressed in a part of the brain called the diencephalon — an area previously found to differ in gay men.
Chromosome 14 also contains a gene that’s thought to be associated with homosexuality: the thyroid stimulating hormone receptor, or TSHR. The find bolsters previous observations linking unusual thyroid function to sexual orientation.
Researchers emphasize that although the new genetic regions provide targets for further research, the potential connections remain speculative. And there are many other studies complicating these findings. One, in particular, indicated that biological sex makes a difference and that identical twins can have different sexual preferences. This goes without mentioning the moral dilemmas inherent in this kind of research.
At this point, not much is clear. But as genetic studies become more advanced, so will research into the intersection of genetics and sexuality.
Regardless, a better understanding of how our genes influence our sexual preferences may illuminate the experiences of gay and straight alike.