The decision by the IOC (International Olympic Committee) to use the SRY gene test to determine eligibility in women’s events is “overly simplistic”, according to the scientist who discovered it.
In a major change to its policy, the IOC announced last week that it will reintroduce gender testing at the 2028 Los Angeles Games, barring transgender women from competing in women’s categories.
Admission to women’s Olympic competitions “is now reserved for people of female biological sex”, who do not carry the SRY gene, the IOC explained in a statement following a meeting of its executive committee.
The IOC will use “a unique SRY gene detection test”, which looks for the presence of a gene on the Y chromosome, known as SRY, as an indicator to determine an athlete’s sex. It will be carried out using a saliva sample, a mouth swab or a blood sample.
The president of the IOC, Zimbabwean Kirsty Coventry, stated that “the policy we announced is based on science and was developed by medical experts.”
But Australian professor Andrew Sinclair, who discovered the SRY gene in 1990, maintained that it is not an adequate test in itself.
“The IOC states that the SRY gene is a reliable test for determining biological sex and, therefore, deciding who can compete in women’s events,” it said in a statement issued on Monday night (30). “However, 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 and involves multiple genes in addition to SRY in developmental pathways, as well as hormones,” added the scientist. “The presence or absence of the SRY gene does not determine the range of human sexual characteristics.”
Sinclair, deputy director of Melbourne’s Murdoch Children’s Research Institute, was equally critical when World Athletics (the international athletics federation) opted to use the test to determine biological sex last year.
“The only thing the SRY test indicates is whether the gene is present or not,” he said. “It does not indicate how SRY is working, whether a testicle has been formed, whether testosterone is being produced and, if so, whether the body can use it.”
According to Sinclair, “the SRY gene alone should not determine who can compete in women’s sports.”
His position was supported by Vincent Harley, an expert on sex-determining chromosomes at the Center for Endocrinology and Reproductive Health in Melbourne: “the presence of the SRY gene does not define sex in all cases.”
Supports and disagreements
“A transgender female athlete may carry the SRY gene; there is little scientific evidence that the gene provides physical advantages in sport,” highlighted Harley.
But not all scientists agree.
Peter Koopman, recognized as co-developer of the SRY gene, classified the IOC’s decision as reasonable.
“It’s clear that the IOC had to do something to address the issue of fairness in sex-differentiated competitions,” said Koopman, professor emeritus at the University of Queensland. “The proposed test for SRY is a good starting point. It is science-based, non-invasive, simple to perform and unobtrusive.”
According to Koopman, “although some maintain that the test’s accuracy is not 100%, this may be a case where the IOC should not allow the perfect to be the enemy of the good.”
Gender testing was first introduced at the Mexico City Olympic Games in 1968 and was last used at Atlanta 1996, before being abolished.
