World Athletics' mandatory SRY gene test for women athletes is totally misguided

The geneticist who discovered the SRY gene on the human Y chromosome explains why it being present doesn't prove what people think it does

- By Andrew Sinclair

Sebastian Coe, the president of World Athletics, recently announced a new rule for women athletes that requires them to undergo mandatory genetic tests to verify their biological sex.

This test must be done if athletes wish to compete at the World Athletics Championships in Tokyo in September.

World Athletics has said all athletes competing as women must have an SRY gene test to identify whether a male Y chromosome is present. As the SRY gene is found on the Y chromosome, it is, in effect, a proxy for the Y chromosome.

Any athlete whose test shows the presence of the SRY gene will be banned from competing in the women's category in elite events. However, if the athlete has a condition called complete androgen insensitivity syndrome, they may be able to qualify for an exemption.

Coe said the decision had been made to ensure “the integrity of women’s sport”, with World Athletics asserting that the SRY gene is a reliable proxy for determining biological sex.

I argue that the science does not support this overly simplistic assertion. I should know, because I discovered the SRY gene on the human Y chromosome in 1990. I have been researching it and other genes required for testis development for 35 years.

Brief primer on testes and ovary development

If a human embryo has XY chromosomes, then at six weeks of development the SRY gene on the Y chromosome triggers a cascade of events involving some 30 different genes that lead to the formation of testes.