Congenital adrenal hyperplasia overview


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Overview
Congenital adrenal hyperplasia (CAH) refers to any of several autosomal recessive conditions resulting from biochemical paths of the steroidogenesis of cortisol from cholesterol by the adrenal glands. Most of these conditions involve greater or lesser production of sex steroids and can alter development of primary or secondary sex characteristics in affected infants, children, and adults. Only a small minority of people with CAH can be said to have an intersex condition, but this attracted American public attention in the late 1990s and many accounts of varying accuracy have appeared in the popular media. Approximately 95% of cases of CAH are due to 21-hydroxylase deficiency.

Examples of conditions caused by various forms of CAH:
 * ambiguous genitalia, in some females, such that it can be initially difficult to determine sex
 * vomiting due to salt-wasting leading to dehydration and death
 * early pubic hair and rapid growth in childhood
 * precocious puberty or failure of puberty to occur (sexual infantilism: absent or delayed puberty)
 * excessive facial hair, virilization, and/or menstrual irregularity in adolescence
 * infertility due to anovulation
 * hypertension

Diagnosis
Prenatal diagnosis can be made in both of these disorders by chorionic villous sampling, but this can only be done at 8-10 weeks. In order to prevent the deleterious effect of excess androgens on genital (and brain!) development, therapy must be started earlier. This is most often considered if there is an affected sibling. Treatment is dexamethasone, which is not degraded by the placenta, but is associated with significant maternal weight gain, hypertension, and edema.