New genetic links to same-sex sexuality found in huge U.S. study

Genome-wide research on DNA from nearly half a million U.S., U.K. adults found five genetic variants

The largest study of its kind found new evidence that genes contribute to same-sex sexual behaviour, but it echoes research that says there are no specific genes that make people gay.

The genome-wide research on DNA from nearly half a million U.S. and U.K. adults identified five genetic variants not previously linked with gay or lesbian sexuality. The variants were more common in people who reported ever having had a same-sex sexual partner. That includes people whose partners were exclusively of the same sex and those who mostly reported heterosexual behaviour.

The researchers said thousands more genetic variants likely are involved and interact with factors that aren’t inherited, but that none of them cause the behaviour nor can predict whether someone will be gay.

The research “provides the clearest glimpse yet into the genetic underpinnings of same-sex sexual behaviour,” said co-author Benjamin Neale, a psychiatric geneticist at the Broad Institute in Cambridge, Massachusetts.

“We also found that it’s effectively impossible to predict an individual’s sexual behaviour from their genome. Genetics is less than half of this story for sexual behaviour but it’s still a very important contributing factor,” Neale said.

The study was released Thursday by the journal Science. Results are based on genetic testing and survey responses.

Some of the genetic variants found were present in both men and women. Two in men were located near genes involved in male-pattern baldness and sense of smell, raising intriguing questions about how regulation of sex hormones and smell may influence same-sex behaviour.

Importantly, most participants were asked about frequency of same-sex sexual behaviour but not if they self-identified as gay or lesbian. Fewer than 5% of U.K. participants and about 19% of U.S. participants reported ever having a same-sex sexual experience.

The researchers acknowledged that limitation and emphasized that the study’s focus was on behaviour, not sexual identity or orientation. They also note that the study only involved people of European ancestry and can’t answer whether similar results would be found in other groups.

PHOTOS: 50 years of LGBTQ pride showcased in protests, parades

Origins of same-sex behaviour are uncertain. Some of the strongest evidence of a genetic link comes from studies in identical twins. Many scientists believe that social, cultural, family and other biological factors are also involved, while some religious groups and skeptics consider it a choice or behaviour that can be changed.

A Science commentary notes that the five identified variants had such a weak effect on behaviour that using the results “for prediction, intervention or a supposed ‘cure’ is wholly and unreservedly impossible.”

“Future work should investigate how genetic predispositions are altered by environmental factors,” University of Oxford sociologist Melinda Mills said in the commentary.

Other experts not involved in the study had varied reactions.

Dr. Kenneth Kendler a specialist in psychiatric genetics at Virginia Commonwealth University, called it “a very important paper that advances the study of the genetics of human sexual preference substantially. The results are broadly consistent with those obtained from the earlier technologies of twin and family studies suggesting that sexual orientation runs in families and is moderately heritable.”

Former National Institutes of Health geneticist Dean Hamer said the study confirms “that sexuality is complex and there are a lot of genes involved,” but it isn’t really about gay people. “Having just a single same sex experience is completely different than actually being gay or lesbian,” Hamer said. His research in the 1990s linked a marker on the X chromosome with male homosexuality. Some subsequent studies had similar results but the new one found no such link.

Doug Vanderlaan, a University of Toronto psychologist who studies sexual orientation, said the absence of information on sexual orientation is a drawback and makes it unclear what the identified genetic links might signify. They “might be links to other traits, like openness to experience,” Vanderlaan said.

The study was a collaboration among scientists including psychologists, sociologists and statisticians from the United States, United Kingdom, Europe and Australia. They did entire human genome scanning, using blood samples from the U.K. Biobank and saliva samples from customers of the U.S.-based ancestry and biotech company 23andMe who had agreed to participate in research.

Lindsey Tanner, The Associated Press

Like us on Facebook and follow us on Twitter.

Just Posted

Castlegar teen cited for drinking and driving near Rossland

The 17 year old put his car in a ditch.

Crown declines to lay charges in Castlegar spree

RCMP were called to eight incidents regarding the same person in a six hour time frame.

Report shows Castlegar’s cemetery has room for next 25 years

The city has developed a master plan for Park Memorial Cemetery.

Snowfall warning for Kootenay and Paulson passes

Up to 30 cm expected in mountain passes Saturday and Sunday.

Readers’ theatre comes to Castle Wood Village

Volunteers and residents gather for a bit of fun at one of Castlegar’s senior residences.

Cold, stormy winter forecast across much of Canada, The Weather Network predicts

In British Columbia temperatures will be slightly above normal and precipitation will be just below normal

29 B.C. students in Hong Kong amid tense protests, university siege

Eight UVic and 21 UBC students still in Hong Kong

‘Midget’ no more: Sweeping division name changes coming to minor hockey in Canada

Alpha-numeric division names will be used for the 2020-2021 season and beyond

Ottawa urges CN and union to continue talks as 3,200 workers go on strike

The rail workers began their strike after failing to reach a deal by a midnight deadline

Student tells B.C. Supreme Court she wasn’t allowed to leave Indigenous smudging ceremony

Girl cross-examined Monday in Nanaimo courtroom, case continues Tuesday

Trans Mountain received $320M in government subsidies in first half 2019: report

The money included $135.8 million in direct subsidies and $183.8 million in indirect subsidies

UPDATED: Vancouver Island’s Joe gets suspended sentence in Teddy the dog cruelty case

Melissa Tooshley expected in court on Thursday in same case

Nineteen boats carrying invasive mussels stopped at B.C. borders

Waters of Columbia-Shuswap still test mussel-free

Woman ‘horrified’ after being told to trek 200 kilometres home from Kamloops hospital

‘I can’t get from Kamloops back to 100 Mile House injured, confused… no shoes, no clothes whatsoever’

Most Read