Congenital adrenal hyperplasia

Congenital adrenal hyperplasia is a group of genetic conditions characterized by abnormal production of several hormones produced by the adrenal glands, including those responsible for sexual characteristics. It can affect the development of both primary and secondary sexual characteristics. It can affect people of either sex. Symptoms first develop in the fetus during the second month of pregnancy and are usually apparent at birth. However, all infants are now routinely screened for one form of the condition which can be treated with hormones as long as they are administered early enough.
Sexual symptoms can vary widely, including precocious puberty and failure to pass through puberty at all. It also affects the hormones responsible for balancing mineral ions in the body, which can lead to vomiting and dehydration.
In most cases, the condition can be diagnosed from its symptoms and tests of hormone levels, but genetic testing is definitive. 
Hormone treatment is possible at any age, but is becoming increasingly controversial due to concerns about imposing gender norms on what, in many cases, can be a benign condition.
Congenital adrenal hyperplasia at Wikipedia
Category:Genetics