The International Olympic Committee’s decision to use the SRY gene test to determine eligibility in women’s events has been labeled “excessively simplistic” by the scientist who discovered the gene.
Last week, the IOC announced a major policy shift, reintroducing gender verification tests for the 2028 Los Angeles Games and barring transgender women from competing. According to an IOC statement, eligibility for women’s Olympic competitions “is now reserved for individuals of biological female sex” who do not carry the SRY gene. The test, which detects the presence of the SRY gene on the Y chromosome, will be administered through saliva, a buccal swab, or a blood sample.
IOC President Kirsty Coventry defended the move, saying, “The policy we announced is based on science and was developed by medical experts.”
However, Australian professor Andrew Sinclair, who identified the SRY gene in 1990, argued that relying solely on this test is inadequate. “The IOC claims the SRY gene is a reliable test for determining biological sex and thus who can compete in women’s events,” he stated in a release Monday night. “But this policy is based on the overly simplistic idea that the presence of the SRY gene alone equates to being male.”
“Male sex is much more complex, involving multiple genes beyond SRY in developmental pathways, as well as hormones,” Sinclair added. “The presence or absence of the SRY gene does not determine the full range of human sexual characteristics.”
Sinclair, deputy director of the Murdoch Children’s Research Institute in Melbourne, was similarly critical when World Athletics adopted the test last year. “The SRY test only indicates whether the gene is present or not,” he said. “It doesn’t indicate how SRY is functioning, whether a testicle has formed, whether testosterone is produced, or if the body can use it.”
According to Sinclair, “the SRY gene alone should not determine who can compete in women’s sports.”
His stance was supported by Vincent Harley, an expert in sex-determining chromosomes at the Centre for Endocrinology and Reproductive Health in Melbourne: “The presence of the SRY gene does not define sex in all cases.”
“A transgender female athlete may carry the SRY gene; there is scant scientific evidence that the gene provides physical advantages in sports,” Harley noted.
But not all scientists agree. Peter Koopman, recognized as a co-discoverer of the SRY gene, called the IOC’s decision reasonable. “It’s clear the IOC had to act to address fairness in sex-segregated competitions,” said Koopman, a professor emeritus at the University of Queensland. “The proposed SRY test is a good starting point. It’s science-based, non-invasive, simple to perform, and discreet.”
Koopman added, “While some will argue the test isn’t 100% accurate, this may be a case where the IOC cannot let perfection be the enemy of good.”
Gender testing was first introduced at the 1968 Mexico City Olympics and last used in Atlanta 1996 before being discontinued.
