Congenital adrenal hyperplasia refers to a group of inherited adrenal gland disorders. People with this condition do no produce enough of the hormones cortisol and aldosterone, and produce too much of androgen.
Congenital adrenal hyperplasia can affect both boys and girls. People with congenital adrenal hyperplasia lack of an enzyme needed by the adrenal gland to make the hormones cortisol and aldosterone.
Without these hormones, the body produces more androgen, a type of male sex hormones. This causes early (or inappropriate) appearance of male characteristics.
Newborn girls with this disorder have a swollen clitoris with the urethral opening at the base (ambiguous genitalia, often appearing more male than female). The internal structures of the female reproductive tract (ovaries, uterus, and fallopian tubes) are normal. As the female grows older, some features start to appear male, such as deepening of the voice, facial hair, and failure to menstruate at puberty.
No obvious problems are seen in newborn males, but changes can be seen long before puberty normally occurs. The child becomes increasingly muscular, the penis enlarges, pubic hair appears, and the voice deepens. Boys may appear to enter puberty as early as 2-3 years of age. At puberty, the testes are small.
Some forms of congenital adrenal hyperplasia are more severe and cause adrenal crisis in the newborn due to salt wasting. In this salt-losing form of congenital adrenal hyperplasia, newborns develop severe symptoms shortly after birth, including vomiting, dehydration, electrolyte changes, and cardiac arrhythmias. Untreated, this condition can lead to death within 1 to 6 weeks after birth.
About 1 in 10,000 to 18,000 children are born with congenital adrenal hyperplasia.