Question

Introduction: Caster Semenya is world class track star from South Africa. She won the 2012 and 2016 Olympic gold medals for the 800 meters and has won the World Track and Field Championships multiple times. She is 46XY genetically with a female phenotype.

1. Does her genotype correspond with her phenotype? What could explain a mismatch between her genotype and phenotype?

2. She has a diagnosis called differences in sexual development (DSD) which covers wide range of conditions. Her blood levels of testosterone are high. Does this provide a clue to her specific DSD condition?

3. Would high testosterone (hyperandrogenism) concentrations provide an advantage for her in this type of race? If so, how?

4. Some other women runners filed a protest against her competing as a woman and the International Association of Athletic Federations (IAAF) ruled that to compete she and other female athletes should have plasma testosterone concentrations below 5 nmol/L. The average for female track and field athletes is 1.8 nmol/L. To lower her testosterone concentrations she would have to take a drug that acts like progesterone. How would this drug work to lower testosterone secretion?

5. This question has no right or wrong answer but is your opinion. Should Caster Semeneya be allowed to run in women’s track and field events without taking the testosterone suppressor?

Answer 1

1. XY genotype is male. So the genotype of Caster does not correspond to phenotype. The condition is called 46Xy DSD. This happens because of some defective genes or because of bodies insensitivity to ex hormones produced. Though the sex hormones are produced, the body cells are not recognizing or responding to it. That is why the phenotype is completely different.

2. The athletes blood testosterone levels are high. Which means the girl is genetiically male and producing testosterone, the body cells are not recognizing or responding to appropriately to testosterone. That is the the sexual organs have not developed correctly.

3. High levels of testosterone have great advatage in such races. This is because, testosterone helps in the growth of muscles in the body. Females have very low testosterone levels in the body. More testosterone, more muscle growth int he body. Endurance in such a race will provide great advatage over other female. Other female wil not have sucha an endurance, that is why she could win.

4. Both testosterone and progesterone are steroid hormones. Progesterone will make aher more sensitive to female hormone and lower the testosterone levels.