Genetics, gender and justice: the legal implications of genetic testing for gender eligibility in sport

World Athletics (WA) and World Boxing have recently reinstated genetic testing for all athletes competing in female categories in world-ranking competitions to determine biological sex. While framed as a mechanism to ensure fairness and protect the integrity of female sport, the move raises complex ethical, legal and scientific concerns and reignites the enduring and highly polarised debate around gender eligibility in sport. The regulation of gender diverse athletes in the female category, those with differences of sex development (DSD) and transgender women, is under scrutiny in the current political climate. The reintroduction of genetic testing in sport renews inquiries about the legality of using genetics to determine eligibility. This article examines whether it is a proportionate and justifiable means of achieving fairness and integrity in female sport or whether it compromises athletes’ rights to dignity, privacy and non-discrimination. The regulation of gender eligibility in sport is not new, with sex testing previously used by WA and the International Olympic Committee (IOC) to police the female category and eradicate perceived unfair advantages in gender diverse athletes. Suspicion-based invasive physical examinations were replaced by chromosomal testing and hormone assessments. However, these were discredited as inconsistent, scientifically flawed and unethical.1 Y chromosome-based testing was also rejected since biological sex is not binary and cannot be conclusively determined through genetic testing alone. Policies have progressed since then, with international and national sport governing bodies responsible for developing their own eligibility criteria through stakeholder consultation. For instance, World Rugby was the first international sport federation to lead a multidisciplinary transgender participation working group, where experts presented evidence relating to sex differences in sport performance, male-associated biological advantage and injuries in sport.2 In 2020, World Rugby attributed the differences in injury metrics between men and women to biological and physiological factors and concluded that …