The phenotypic expression of selective disorders of male sexual differentiation.

Normal male sexual differentiation is the result of a series of individual steps that occur in an orderly fashion: testicular differentiation, müllerian regression, wolffian duct development, differentiation of the urogenital sinus and external genitalia, phallic growth and descent of the testes. Herein we present the pathophysiological mechanism by which selective disorders disrupt these normal events and produce specific phenotypes.