The Olympic Committee will require women athletes to take a gene test showing they’re biologically female before they can compete.
Athletes’ gender will be determined by a genetic test, which looks for the presence of a gene on the Y chromosome, known as SRY, as a proxy for the sex of an athlete.
With “rare exceptions” for those who have differences in sex development, those who test positive will only be allowed to compete in male categories.
The policy, to be introduced from the 2028 Olympics, also affects qualifying events and the Youth Olympics.
The SMC asked experts to comment.
Professor Andrew Shelling, geneticist, and Director of the Centre for Cancer Research at the University of Auckland, comments:
“Recent media coverage has highlighted questions about sex-determining tests used in sport.
“The SRY (Sex Determining Region on the Y chromosome) gene is the key trigger of typical XY (male) development and is widely regarded as biologically relevant, and the test is technically robust and reliable in most cases. An SRY-positive result (indicating the person has a Y chromosome leading to the formation of testes) results in ineligibility for the female category under the new rules for the Olympics, unless specific exemptions (such as certain cases of androgen insensitivity syndrome are met).
“However, we know that biology is not binary. Rare but well described conditions, such as differences of sex development, gene mutations, chromosomal translocations, mosaicism, and/or androgen insensitivity syndromes mean SRY status alone does not fully describe an individual’s biology. Any eligibility framework must take into account a range of information, not just include SRY gene testing and acknowledge that genetics, hormones, and physiology interact in complex ways.”
“Because genetic information can have long‑term personal and familial implications, it is treated with particular care in both the clinical arena and therefore should be also in sport. This is especially important for young people, where safeguarding, consent, and privacy protections are critical.”
Conflict of interest statement: “No conflict of interest.”
Dr Ben Albert, Paediatric Endocrinologist and Senior Research Fellow, Liggins Institute, University of Auckland, comments:
“The International Olympic Committee have announced that they will use a genetic test for SRY to determine whether an athlete is eligible to compete as a woman in athletic events. The SRY gene is the initial switch in development that if present sets an embryo on the pathway to become a biological male. With quite rare exceptions it will be a reliable way to indicate if whether someone was born with a biological male body, and experienced male puberty with high levels of testosterone, the hormone that drives it. Testosterone does have important effects on physical characteristics including causing men to have greater muscle mass and greater physical performance, on average, than women.
“Trans-women, will be excluded from competing as women due to this new test. There will be contrasting opinions on whether this is fair, which is a moral issue for society and the sporting agencies to tackle.
“Importantly, the IOC has recognised that there are people who have SRY but have variations in how their body works. For example, people with complete androgen insensitivity have the SRY gene and make lots of testosterone, but their body doesn’t respond to it, they appear as female and usually identify as female. The IOC has indicated they will be able to compete with other females. There are many other uncommon variants of how the body produces and responds to testosterone and people with some of these may also be exempt from the SRY rule.”
Conflict of interest statement: “I have no conflict to declare.”
Our colleagues at the AusSMC and UK SMC have also gathered comments. A selection follows.
Associate Professor Rebekah McWhirter is from the School of Law at the Australian National University. Rebekah is Co-chair of Education, Ethics and Social Issues Committee for Human Genetics Society of Australasia.
“This debate appears to be conflating two different groups of people: trans athletes and athletes with differences of sex development.
“This test is not a good way of determining biological sex, so it will not solve any perceived problem of fairness, and it may well cause a great deal of harm to individuals with differences of sex development, who were not previously aware of this.
“Genetic testing of this kind requires appropriate genetic counselling, including a thorough discussion of the risks and possible outcomes, for consent to be in any way valid. This is not a test being done for clinical purposes, but for misguided social reasons, and in a way that misunderstands the science. The athletes will feel they have no choice but to take the test, which violates fundamental principles of medical ethics. The lack of safeguards – such as standardised genetic counselling protocols, privacy protections, and equitable access to testing – further amplifies these harms, particularly in low-resource settings.
“Mandatory testing in contexts where valid consent cannot reasonably be obtained is only justifiable in strictly limited circumstances, and usually where harm to others (e.g. breath testing for alcohol in drivers) or individuals (e.g. anti-doping testing in sport) is a legitimate risk. As SRY gene testing neither protects against harm nor ensures fairness in sport, it is not justifiable to impose upon athletes unable to consent freely to testing.”
Rebekah has declared: Gabrielle Reid and I are co-chairs of the Education, Ethics and Social Issues Committee for HGSA and jointly prepared the below statement. Further, you can find the official HGSA Position Statement on this topic here.