1. Early chromosome and SRY tests (1960s–1990s)

• At the Olympic Games from 1968 onwards, the IOC introduced mandatory “sex tests.”
• Initially simple physical examinations, then chromatin tests (Barr bodies), and later also SRY gene tests.
• Reason: To prevent men from competing in women’s competitions.

2. Ewa Kłobukowska (Poland, 1967)

• European champion, Olympic medalist in athletics.
• Failed an early chromosome test → she had XX/XY mosaicism (intersex variation).
• Result: Lifetime ban, even though she bore no responsibility.

3. María José Martínez-Patiño (Spain, 1985)

• Hurdler.
• Chromosome test showed 46,XY → she had the SRY gene and Androgen Insensitivity Syndrome (AIS).
• Her body developed as female, and she had no advantage from testosterone (because the androgen receptors did not function).
• Nevertheless, she was excluded from competition.
• Later, she strongly campaigned against these tests – with success: in 1999, the IOC abolished blanket chromosome testing.

4. Caster Semenya (South Africa, since 2009)

• 800m runner, multiple world and Olympic champion.
• Examinations revealed 46,XY with functional SRY → testes produced testosterone.
• The International Association of Athletics Federations (IAAF, now World Athletics) therefore introduced testosterone limits:
  • Female athletes with XY/DSD and SRY must lower their testosterone levels medically in order to compete.
• Semenya today (as of 2025) is no longer allowed to compete in her preferred events because she does not want to take medication.

5. Other known cases

• Several anonymous DSD athletes at World Championships and Olympic Games have been flagged in recent decades, but their names were often not disclosed (privacy protection).
• The issue was always the same: SRY gene present → development with increased testosterone → athletic advantage in women’s category.

6. Conclusion

• The presence of the SRY gene was decisive in some cases for top-level performances in women’s sport.
• Most famous examples:
  • Martínez-Patiño (AIS, Spain) → no advantages, but excluded.
  • Caster Semenya (XY with SRY, South Africa) → likely advantages due to higher androgen effects.

For chromosome and SRY tests see:  Sport and XY-DSD (Disorders of Sex Development)