Familial male pseudohermaphroditism with incomplete virilization.

A 21-year-old 46 XY individual with familial male pseudohermaphroditism was investigated. Phenotype consisted of pseudovaginal perineoscrotal hypospadias with bilateral inguinal gonads and a masculine habitus without gynecomastia. Plasma testosterone, cortisol, follicle stimulating hormone, urinary 17-ketosteroids, and 17-ketogenic steroids were within the normal male range. Plasma dihydrotestosterone was at the lower limit of the normal male range. Plasma luteinizing hormone was three times and plasma estradiol was about one and a half times the upper limit of normal for men. These results are consistent with a partial defect in the mechanism of action of testosterone. The differential diagnosis of various forms of male pseudohermaphroditism is discussed.