A new study using big genetic data to find genes underlying sexual orientation is a major scientific step forward, and a good example of carefully presenting a complex topic, CSUN Assistant Professor of Biology Jeremy Yoder wrote in an article for Slate and multiple media appearances on the day of the study’s publication. He noted, however, that research into the biology of sexuality carries risks to LGBTQ people.
… the hazards of this line of research aren’t really mitigated by ethical research practices, in the conventional sense. Those hazards lie not just in how the work is conducted and presented, but in how society receives it.
In addition to the Slate article, Yoder provided perspective and broader context on the new study in interviews with new organizations including the BBC World News, the New York Times, New Scientist, and GEN Genetic Engineering and Biotechnology News.
The study, led by researchers at the Broad Institute, uses genetic data and records of sexual behavior for almost half a million people who contributed to the UK Biobank data repository and customers of the personal genetics company 23andMe in a genome-wide association analysis. This approach "scans" for genes showing associations to whether or not participants reported having had same-sex sexual experiences, and what proportion of their past partners were of the same sex. Even with this very large dataset, only a handful of genes showed associations big enough to identify with statistical confidence, consistent with the prospect that sexual orientation is shaped by a very large number of genes with immeasurably small individual effects, like other human behavioral traits examined in similar studies.
The overall finding that genetics contribute to sexual orientation isn’t new, Yoder notes in Slate — prior studies with twins and along family trees have repeatedly found similar results. It also doesn’t mean that genetics is the full story, as he told Angus Chen in an interview for Public Radio station WBUR:
Sexuality is something you define for yourself, Yoder says. “It’s a very personal thing. It’s about what your experience is. Some of it is genetic, but some of it is your personal history. It’s what you actually do, who you connect with, and how you end up living your life.”
LGBTQ scientists and activists have long had mixed feelings about this kind of research, as Yoder wrote in a previous article about preliminary reports of the study. Information on the biology underlying sexual orientation could provide a basis for a "cure" for homosexuality, and even a list of genes associated with same-sex behavior could be used to develop a genetic test to screen embryos or adults for their sexual orientation.
Reviewing the published study, Yoder notes that the researchers behind it have taken care to make clear that their results could not be used for an effective genetic test of orientation — they pilot a test with independently collected data, and find it has effectively no predictive power. This minimizes the risk of misuse, the CSUN biologist says, but doesn’t eliminate it:
There is, as of now, not much regulation of how genetic data is used once it’s published. Anyone who pays for a personal genomic read from 23andMe can look up whether it registers variants associated with same-sex behavior in the new analysis, regardless of the actual predictive value of those variants. Lack of demonstrated predictive power hasn’t prevented the emergence of startups offering to tailor diet advice to your genetic profile, and even proposing to screen embryos for future traits …
Ultimately, whether the published results will be misused remains to be seen, the CSUN biologist concludes. "I wish I could read this new study purely as an answer to my own curiosity about the biology and evolution of my queer identity. I hope, in the end, that’s all it turns out to be."
Image credit: Markus Spiske