Scientists at the University of California, Los Angeles, have developed an algorithm that uses epigenetic information from nine regions of the human genome to predict whether a man is gay or straight. According to the study, this DNA test can predict the sexual orientation of males with up to 70 percent accuracy by analyzing five epigenetic markers, and all it takes is a swab of saliva.
“To our knowledge, this is the first example of a predictive model for sexual orientation based on molecular markers,” said Tuck C. Ngun, lead researcher of the study who works as a post doctoral fellow at UCLA.
For the study, researchers used saliva samples from 37 pairs of twins in which one twin was homosexual and the other was heterosexual, and 10 pairs in which both twins were homosexual. Researchers further looked into saliva samples to find if there were certain DNA methylation marks associated with the sexual orientation of man, so they analyzed 400,000 methylation marks and ultimately found that five were notably different in gay and straight twins.
“Those five seem to be the most informative,” Ngun said in a statement at BuzzFeed. “They seem to be able to best tell you whether someone is likely to be gay or straight.”
Many experts are skeptical of the study, so they have expressed caution over the controversial results of the study. Experts who are not involved in the study have concerns over potential misuse of the test and this has led Ngun to stop the project entirely, reports New Scientist.
Since the study was based on a relatively small sample of man, Johnjoe McFadden, a molecular geneticists said such studies that associate with biomarkers with particular traits are prone to false positives due to spurious associations that are down to sheer chance.
“The predictive test needs replication on larger samples in order to know how good it is, but in theory it’s quite interesting,” says Micheal Bailey, a professor of psychology at Northwestern University.
Ngun, who is gay himself says he has no intention of pursuing some kind of commercial test to predict sexuality. Ngun thinks that his work could be misinterpreted by people who seek to identify and punish people for being gay, so he has abandoned the project entirely.
“I just left the lab last week,” he says. “I don’t believe in the censoring of knowledge, but given the potential for misuse of the information, it just didn’t sit well with me.”