The Brazilian Volleyball Confederation (CBV) recently implemented a new eligibility rule that requires SRY gene testing for athletes wishing to compete in the women’s sport. This decision, which follows the guidelines of the International Olympic Committee (IOC) announced in March 2026, raises uncertainty about the future of trans athletes in sport, including striker Tifanny Abreu, who plays for Osasco. The measure came into effect on August 18, 2026, with an expected impact on the next national and international volleyball seasons.
Understand what the SRY gene is and how the test works
The SRY gene (Sex-determining Region Y) is fundamental in determining the genetic sex of an individual. In most cases, the presence of this gene on the Y chromosome leads to the development of male characteristics, while its absence results in female characteristics. The formation of the gonads, which differentiate into testes or ovaries, is directly influenced by SRY from the sixth week of gestation onwards.
“With the presence of the SRY gene, the gonad of this fetus will differentiate into a testis; in the absence of SRY, the gonad will differentiate into an ovary”, explained Professor Daniel Gilban, pediatric endocrinologist at the Pedro Ernesto University Hospital (Hupe/Uerj). The test for the SRY gene, although widely used to identify the biological sex of newborns, has several other medical applications.
Ciro Martinhago, geneticist and specialist in rare diseases, details that the test can be requested in cases where there is a discrepancy between the karyotype (set of chromosomes) and the genitalia, such as an individual with karyotype XX (female) who has male genitalia. João Polydoro, orthopedist and specialist in sports medicine at Hospital Alemão Oswaldo Cruz, adds that outside of sport, the test is applied to investigate differences in sexual characteristics, delays in puberty, absence of menstruation, suspected gonadal underdevelopment or infertility. Collection for the exam can be done with a swab on the oral mucosa or through a blood test, with the COI indicating that the result is permanently valid.
Implications of the new rule on the Brazilian sports scene
The Brazilian Volleyball Confederation announced that the new requirements are already in force for important competitions. This includes the Superliga A and B (2026/2027 season), the 2026 Super Cup, the 2027 Copa Brasil, the 2027 Brazilian Beach Volleyball Circuit (adult), the CBVP Challenger 2027, and all subsequent editions during the policy’s validity.
For athlete Tifanny Abreu, the situation is delicate. Despite the new rules, she continues to participate in the Campeonato Paulista for Osasco, as the São Paulo Federation reported that the tournament had started before CBV’s announcement. The São Paulo club expressed support for the player and its legal department is analyzing the legal impact of the decision to determine the next steps.
Questions about SRY test accuracy and exceptions
Medical experts point out that the simplicity of the SRY gene test may not take into account the complexity of human biology. There are several documented cases in medicine of hormonal and sexual development variations that would not be captured by a binary SRY test.
Professor Daniel Gilban criticizes the intention behind the measure. “Basically, what they want is to deny trans people access to sport and they carried out this SRY research because of that,” he stated. He emphasizes that there are women with positive SRY and men with negative SRY. “We have all the differences in sexual development that we call DSD in biomedical sciences, or intersex in social sciences. There is an entire population that does not fit into this binary division of sexual development”, explained Gilban. Ciro Martinhago also recognizes the existence of exceptions, although the SRY test was adopted by the IOC as a guide for eligibility.
International Olympic Committee Commitment to Los Angeles 2028
The new rule announced by the IOC in March 2026 is a milestone for the participation of trans athletes in women’s competitions and is already valid for the Los Angeles Olympic Games in 2028. The SRY gene test requirement seeks to establish a criterion considered more objective for eligibility, but continues to generate intense debate about inclusion and justice in high-performance sport.
Timeline of SRY Gene Testing Decisions
- March 2026:International Olympic Committee (IOC) announces new eligibility rule, which includes the requirement for SRY gene testing for athletes in women’s sports.
- August 18, 2026:Brazilian Volleyball Confederation (CBV) adopts IOC guidelines, requiring SRY gene testing for participation in national competitions.
- 2026/2027 season:The new CBV rule comes into force for important tournaments, such as Superliga A and B, Supercopa 2026, Copa Brasil 2027 and the Brazilian Beach Volleyball Circuit 2027.
- Los Angeles 2028 Olympic Games:The eligibility rule based on the SRY gene test will be fully valid, impacting the selection of athletes.
