In September 2025, World Athletics introduced a mandatory SRY test for all women athletes wishing to compete in the female category at the World Championships in Tokyo.
Framed as a step to “protect the integrity of women’s sport,” the test has triggered heated debates across the scientific, legal, and ethical spectrum. While the SRY gene test has important clinical applications in medicine, its use as a single determinant for athletic eligibility is deeply contested. To understand why, it’s important to explore what the SRY gene is, how it works in biology, and why its application in sport is seen as problematic.
What Is the SRY Gene?
The SRY gene (Sex-determining Region Y) is located on the Y chromosome. Its role is to produce a protein known as the testis-determining factor (TDF), which initiates the development of testes in an embryo. At around six weeks of embryonic development, if the SRY gene functions normally, it triggers a cascade of other genes, leading to the formation of testes, testosterone production, and the development of male-typical traits. In the absence of a functioning SRY gene, the embryo develops ovaries and female-typical traits.
This makes the SRY gene crucial in sex determination. But here lies the catch: sex development is not dictated by this single gene alone. Many other genes and hormonal processes are involved, and variations at any stage can result in differences of sex development (DSDs).
The SRY Test in Clinical Medicine
In medicine, the SRY test is a diagnostic tool. Doctors use it to help identify certain DSDs, such as:
- Swyer Syndrome (46,XY gonadal dysgenesis): Individuals have an XY chromosome set, but due to a non-functional SRY gene, they develop female characteristics.
- 46,XX Testicular DSD: Here, an SRY gene is misplaced onto an X chromosome, leading an XX individual to develop male traits.
In these contexts, the SRY test provides clarity for medical treatment and counseling. It is not used as a judgment on identity or eligibility, but as one piece of a larger diagnostic puzzle.
Why World Athletics Introduced the Test
World Athletics President Sebastian Coe announced the test as a “once-in-a-lifetime requirement” for female athletes. Athletes undergo a cheek swab or blood test to check for the presence of the gene. The rationale, according to the governing body, is to create a “clear and objective line” between men and women in sport, after years of disputes over DSD and transgender participation. Previous policies based on testosterone levels were challenged in court and criticized for requiring athletes to undergo medical treatments to lower testosterone.
By turning to a genetic marker, World Athletics argues it has found a simpler, more defensible way to maintain fairness.
Why the SRY Test Is Problematic
1.Biological Complexity : Sex is multi-factorial, shaped by chromosomes, gonads, hormones, and physical traits. The SRY gene is only the trigger it does not dictate outcomes on its own. An individual may have the SRY gene but still develop female anatomy, as seen in conditions like CAIS (Complete Androgen Insensitivity Syndrome).
2.Scientific Criticism : Even Andrew Sinclair, one of the co-discoverers of the SRY gene, has said the test is an oversimplification. Other leading geneticists argue that what matters most in sport like muscle mass or strength is shaped by downstream hormonal processes, not just by the presence of SRY.
3.Ethical Concerns : Forcing athletes to undergo genetic testing to prove their eligibility raises serious privacy and autonomy issues. Athletes may learn about previously undiagnosed DSD conditions through such tests, potentially causing distress.
4.Discrimination Against DSD Athletes : History shows that sex verification tests in sport have never uncovered “male impostors.” Instead, they have consistently targeted women with natural variations in sex development, subjecting them to stigma and exclusion. The SRY policy risks repeating that pattern.
The Contradiction: CAIS Exception
Interestingly, World Athletics’ rules allow women with Complete Androgen Insensitivity Syndrome (CAIS) to compete, even though they carry the SRY gene. Because their bodies cannot respond to testosterone, they do not gain the supposed athletic advantages of male puberty. This exception undermines the very basis of the policy: if SRY is supposedly the definitive marker of sex, why make an exception? The answer reveals the real motive excluding athletes who have benefited from male puberty which the SRY test does not actually measure.
A Troubled History of Sex Testing in Sport
The SRY test is the latest in a long line of controversial verification methods:
- 1950s–1960s: Invasive physical examinations and “femininity certificates.”
- 1968–1990s: Chromosomal tests (Barr body test), later abandoned after wrongful exclusions.
- 2010s–2020s: Testosterone regulations, which led to legal battles involving athletes like Caster Semenya and Dutee Chand.
Each method was eventually abandoned for being scientifically flawed and ethically problematic. The SRY test risks being another repeat in this cycle. World Athletics describes the SRY test as “once-in-a-lifetime and highly accurate.” But experts warn of risks:
- Sample contamination: Even a single stray male cell could produce a false positive.
- Lack of quality control: With no central testing lab, results may vary by country.
- Psychological harm: Athletes could face stigma or identity crises if labeled “ineligible.”
The SRY test debate is about more than eligibility it’s about the future of women’s sport, athlete dignity, and scientific integrity. At its core, the question is whether fairness can be ensured without resorting to reductive, exclusionary measures. For Indian athletes and others worldwide, the policy could mean added layers of scrutiny and anxiety, even for those with no prior reason to question their eligibility.
Experts recommend moving beyond single-marker tests like SRY and adopting a multi-factorial, athlete-centered approach:
- Consider multiple factors hormonal, gonadal, anatomical rather than one gene.
- Protect athlete dignity with confidentiality and medical support for those affected.
- Involve diverse stakeholders, scientists, ethicists, lawyers, and athletes in policymaking.
- Shift the debate from “who is a woman” to how to create fair and inclusive categories without harming athletes.
The SRY gene test may appear to offer a simple solution to a complex issue, but it falls short both scientifically and ethically. While useful in medicine, it cannot serve as a definitive gatekeeper for eligibility in women’s sport. By reviving a discredited form of genetic screening, World Athletics risks not only undermining athletes’ trust but also excluding women who have every right to compete. As the debate intensifies, one truth stands out: fairness in sport cannot come at the expense of dignity and human rights.
