The Women's Tennis Association is introducing a genetic screening requirement for players on the women's tour. Under the policy, eligibility will be confirmed through a required, one-time screening for the SRY gene, carried out by cheek swab or blood test.
Al Jazeera reports the policy takes effect on Tuesday, with screening of players beginning this year. It replaces an earlier framework under which transgender women could compete after maintaining lowered testosterone levels for two years.
What the test does
SRY is a short stretch of DNA usually carried on the Y chromosome. In fetal development it acts as the trigger for the formation of testes rather than ovaries. A screening test detects whether the gene is present.
The practical argument for using a single genetic marker is that a person's DNA does not change, so the screening only has to be done once, unlike hormone testing, which requires monitoring over time.
The governing body has not publicly set out what follows a positive result, or what happens to a player who declines to be tested. Those details are not specified in the material released so far.
Not the first
Tennis is following other governing bodies rather than leading them.
World Athletics introduced an SRY gene test for the female category in 2025. The International Olympic Committee has set out a comparable policy for the female category, with limited exceptions for certain differences in sex development, including complete androgen insensitivity syndrome.
The direction of travel across international sport has been consistent: away from hormone thresholds and toward a one-off genetic screen.
The scientific objection
The dispute is not only political. Some geneticists argue that a single marker is the wrong instrument for the question being asked.
Their case is that sex development is produced by a network of genes and hormonal signals rather than by one switch, and that outcomes vary. The clearest example is complete androgen insensitivity syndrome, in which a person has the SRY gene but the body cannot respond to testosterone. In that case, the argument runs, the presence of the gene does not by itself indicate a performance advantage, which is what eligibility rules are meant to be measuring.
Supporters of screening counter that hormone-based rules proved difficult to administer and to enforce consistently, and that a clear, stable eligibility line is preferable to case-by-case adjudication.
The rights objection
Human Rights Watch has argued that testing all women athletes is discriminatory, on the grounds that it singles out competitors by sex characteristics and that consent is not meaningful when refusing the test ends a career.
Critics also point to the history. Sex testing in sport has been applied to women and not to men, and past testing regimes fell hardest on athletes from the global south, several of whom were publicly identified and lost their careers.
Where prominent figures stand
Opinion within the sport is genuinely divided, and has been for years.
Al Jazeera notes that Billie Jean King has regarded the exclusion of transgender players as discriminatory, while Martina Navratilova has been an outspoken critic of their inclusion in the women's game. Aryna Sabalenka, the world number one, has said it would be unfair for women to have to face transgender opponents.
How many players this affects
One fact is not disputed by any side: there are no known transgender women currently competing in professional tennis.
The best-known case in the sport's history is Renée Richards, who played on the women's tour in the 1970s after a court challenge. Nearly fifty years later, the tour is adopting a screening requirement for every player in a field where no affected player is known to be competing.
That gap, between the breadth of the rule and the number of people it currently touches, is much of what the argument is now about.
