Sexual development, normal and abnormal.

An understanding of normal sexual development is essential to understanding abnormal sexual development. Normal differentiation of the bipotential external genitalia, reproductive ducts, and gonads are dependent upon the presence or absence of androgens from any source, the presence or absence of mullerian inhibiting factor from the fetal testes, and the number and type of sex chromosomes present respectively. Abnormal differentiation results from an imbalance of one or more of these factors or peripheral resistance to these factors.