Scientists might be getting closer to finding the genetic source for homosexuality, after a team announced it had identified gene regions that appeared to be linked to the sexual orientation — but not everyone is buying it.
A study published in the journal Scientific Reports highlights genes that have previously been shown to be crucial for brain development and thyroid gland function. It specifically points to two genes called SLITRK5 and SLITRK6 that reside on the 13th chromosome. SLITRK6 is especially active in the diencephalon, an area in the brain that includes the hypothalamus, which is “a region previously reported as differing in size in men by sexual orientation,” the study notes. According to the research, genes that are linked to neurodevelopment and to traits related to the nervous system “are also of potential relevance to behavioral phenotypes such as sexual orientation.”
Another chunk of DNA the researchers identified was the TSHR gene on chromosome 14, which is linked to the thyroid.
Some scientists have previously suggested that thyroid hormones, including those produced by a pregnant mother, can affect sexual orientation.
The researchers identified those genes when they compared the DNA of about 1,000 gay and 1,200 straight men, most of whom had European ancestry.
Although previous investigation has suggested a genetic link to sexual orientation, this study pinpoints specific pieces of the genetic code that could be involved in the development of that orientation.
It was unclear whether the results could extend to lesbians and straight women, as the scientists did not analyze female DNA in this study. It was also unclear how the findings relate to orientations other than homosexuality, such as bisexuality and asexuality.
Some experts, however, were skeptical that the findings could even have…