The Women's Tennis Association (WTA) has announced that all female professional tennis players must undergo a mandatory genetic screening test — a cheek swab analysing the presence of the SRY gene, located on the Y chromosome — in order to compete in WTA tournaments. The decision follows pressure from the International Olympic Committee, which introduced similar testing in March 2025 at the urging of US President Donald Trump, who seeks to bar transgender and intersex athletes from women's events at the 2028 Los Angeles Olympics. Critics, including Andrew Sinclair — the geneticist who first identified the SRY gene — argue the test is scientifically inadequate, as it cannot determine whether the gene is functional, whether testosterone is produced, or whether the body can utilise it; WTA founder Billie Jean King has also spoken out against the exclusion of transgender athletes from sport.