New Research Shows Epigenetic Markers For Sexual Orientation, Lead Scientist Calls For More Advanced Research

Researchers say they have may discovered a way to predict male sexual orientation by looking at epigenetic markers that control human DNA function, according to a presentation given to the American Society of Human Genetics in Baltimore, Thursday.

“To our knowledge, this is the first example of a predictive model for sexual orientation based on molecular markers,” lead researcher Tuck Ngun of the David Geffen School of Medicine of the University of California, Los Angeles, wrote in a statement. The scientist warns that the research still has some limitations, still needs to be peer reviewed and published, and the subject size was limited, but believes they made a noteworthy discovery.

By looking into the genes of 37 pairs of male, identical twins in which one brother was homosexual and the other brother was heterosexual, as well as 10 sets of brothers who were both homosexual, the research team says they discovered specific epigenetic markers in nine different areas of the genome that might be able to predict the odds of sexual orientation correctly seven out of 10 times. The researchers say molecular “switches” in humans, technically termed the epigenome, can both turn on or silence genes within human DNA. These switches, scientists suspect, can be turned on or off in a variety of ways, including exposure to chemicals and experiences. For example, an earlier Inquisitr article explained that recent study of the epigenome of Holocaust survivors showed genetic evidence that trauma can cause DNA changes that can be passed along to subsequent generations.

Research into epigenetic inheritance conducted on Holocaust survivors has demonstrated scientific evidence of the transmission of trauma onto one’s descendants, but this idea is nothing new for Native Americans, who still hold onto traditional beliefs of their ancestors.

The Mount Sinai research team, led by Rachel Yehuda, examined the genes of 32 Jewish individuals who had witnessed torture or experienced torture, been interned in a concentration camp by Nazi forces, or been forced into hiding during the era of the second world war. The team also examined their children’s genes. Children of holocaust survivors are known to have an increased likelihood of suffering from stress disorders, but earlier research into possible epigenetic inheritance led these scientists to look past child-rearing differences at the actual genes of these descendants of holocaust survivors. What they found surprised a lot of people, but apparently came as absolutely no surprise to Native Americans.

Some geneticists caution that the findings presented at the meeting Thursday are too premature to draw any conclusions from, according to Science Daily.

“The question as to whether that prediction is going to be useful outside of the small number of twins in the study is really unclear,” a genetics professor at the University of Utah, named Dr. Christopher Gregg, commented.

“One thing you can clearly see is that the sample size is too small,” Dr. Peng Jin, professor of human genetics from Emory University in Atlanta, criticized. “They don’t have enough power to make that claim.”

The Atlantic strongly criticized the researchers’ presentation.

Still, the researchers still believe the study is an important step. Ngun reiterates that he never once claimed to have discovered the ‘gay gene(s)’, but rather presented results worthy of further investigation.

Online, Ngun defended his research against the article in the Atlantic.

“I am not interested in a public argument but Ed made fundamentally inaccurate claims that could damage my professional reputation. I would have appreciated the chance to explain the analytical procedure in much more detail than was possible during my 10-minute talk but he didn’t give me the option.

“Essentially, Ed’s claim that inappropriate statistics were used is not credible because he clearly misunderstood the analytical procedure. This is not a matter of opinion. He mischaracterized several crucial things…”

Ngun reportedly got into this line of genetic research, because he wanted to understand himself better. Reportedly, the knew very early in life that he was gay, according to BuzzFeed.

“I didn’t necessarily have a word for it at the time, but I knew from like 5 years old that I was not quite the same as my other guy friends.”

One thing everyone in the field agrees on is that there is probably not one single gene that causes homosexuality, NBC reported. That same NBC report got into more details of the research, explaining that Ngun and his team created a computer algorithm that seemed to show patterns of methylation in nine regions, and that it was associated with sexual orientation with 67 percent of the time.

On a more celebratory note, the presentation on epigenetics and sexual orientation was given just in time for National Coming Out Day, which is being celebrated Sunday on Twitter using the hashtag: #NationalComingOutDay.

[Photo via Tuck Ngun | Public Twitter photo]