Friday, August 30, 2019

Study on the genetic basis of human sexuality

Nature News has the scoop here on the latest study (published in Science here) into the genetics of sexual orientation.

A sample from the news item:

The largest study to date on the genetic basis of sexuality has revealed five spots on the human genome that are linked to same-sex sexual behaviour — but none of the markers are reliable enough to predict someone’s sexuality.

....Although some researchers and LGBTQ advocates might question the wisdom of conducting this kind of research, Birney says that it’s important. There has been a lot of sociological research on same-sex sexual behaviours, he says, but this is an incredibly complicated topic. It’s time to bring a strong, biologically based perspective to the discussion, Birney says.

The abstract for the study:

Twin and family studies have shown that same-sex sexual behavior is partly genetically influenced, but previous searches for specific genes involved have been underpowered. We performed a genome-wide association study (GWAS) on 477,522 individuals, revealing five loci significantly associated with same-sex sexual behavior. In aggregate, all tested genetic variants accounted for 8 to 25% of variation in same-sex sexual behavior, only partially overlapped between males and females, and do not allow meaningful prediction of an individual’s sexual behavior. Comparing these GWAS results with those for the proportion of same-sex to total number of sexual partners among nonheterosexuals suggests that there is no single continuum from opposite-sex to same-sex sexual behavior. Overall, our findings provide insights into the genetics underlying same-sex sexual behavior and underscore the complexity of sexuality.