Question

In an XX fetus with severe CAH, external genitalia will usually be male. Describe two possible situations where an XX fetus with severe CAH could instead develop female external genitalia. For each situation, explain how it would lead to the development of female external genitalia in the presence of high levels of testosterone.

Answer 1

Classic CAH may have a condition called ambiguous genitalia , where the genitals might look like that of a male child or where the female genital (clit) is enlarged. In this case the infant will be seriously affected by lack of cortisol, aldosterone or both causing adrenal crisis, which can be life threatening.

In nonclassic CAH the infants don’t show any symptoms. The blood screening also doesn’t show anything. It develops in late childhood or early adulthood , where cortisol maybe the only hormone that’s deficient. Female infants might have normal genetalia at birth but later may experience irregular or absent menstrual periods, masculine characters such as facial hair/body hair, deepening of voice etc.

High testosterone might result in early puberty or short height in these cases.