[Sex differentiation and its anomalies]

Sex determination and differentiation is a sequential process that involves genetic, gonadal, phenotypic and psychological sex. Sex determination is primarily testis determination. The primary event is differentiation of the gonad; all subsequent sexual differentiation is hormonally controlled. The Authors present a classification of abnormal sexual development and consider the errors of primary sex differentiation (anomalies of sex chromosomes and of gonadogenesis) and the errors of sexual differentiation (inadequate masculinization of genetic male and virilization of genetic female). At the end the clinical approach to disorders of sexual differentiation is briefly considered.