Etiopathogenesis, classification, investigations and diagnosis in intersex disorders.

Abstract

In the last years, advance~ in experimental endocrinology, biochemistry, genetics and molecular biology have all contributed to our understanding of the process of human sex differentiation. In brief, normal sex development consists of three sequential processes. The first is the genetic sex determined at the time of fertilization by the sex chromosome constitution. In the second phase, the genetic information determines that an indifferentiated gonad differentiates either in a testis or an ovary (gonadal sex). Finally, sexphenoO,pe is the result of male differentiation which is an active process resulting of testicular secretions: anti-Miillerian hormone (AMH) produced by the Sertoli cells which inhibits the Miillerian ducts, and testosterone (T) produced by the Leydig cells which is responsible for stabilization of the Wolffian ducts and via its transformation into dihydrotestosterone (DHT) is responsible for virilization of the external genitalia. In the absence of testis, the geni-