Disorders of androgen action cause several types of male pseudohermaphroditism. In such disorders, testosterone formation and Mullerian regression are normal, and impairment of male development is a result of resistance to androgen action in the target cells. 5a-reductase deficiency is an autosomal recessive disorder characterised by:
ΓÇó Severe perineoscrotal hypospadias.
ΓÇó A blind vaginal pouch of variable size, opening either into the urogenital sinus or the urethra.
ΓÇó Testes with normal epididymides, vasa deferentia, seminal vesicles, and ejaculatory ducts that terminate in the blind-ending vagina.
ΓÇó A female habitus without female breast development but with normal axillary and pubic hair.
ΓÇó Absence of female urogenital structures.
ΓÇó Normal male plasma testosterone.
ΓÇó Masculinisation to a variable degree at the time of puberty.
