[Male pseudohermaphroditism due to deficit in the conversion of cholesterol to delta5 pregnenolone (author's transl)].

One patient, aged 13 months, considered phenotipically a female, was admitted with a picture of acute dehydration. Familial history (one sister dead from the same picture at the age of 18 months), clinical data (several episodes of dehydration, dark skin and mucosae, and slight abnormalities in the external genitalia), hormonal examinations (low plasmatic levels of cortisol, aldosterone, androgens and low urinary excretion of 17 hydroxycorticoids, dehydroepiandrosterone and ethiocholanolone), chromosomal examination (karyotype XY) and histological data (normal testis) suggested a diagnosis of male pseudohermaphroditism with complete feminization due to an abnormal conversion of cholesterol in delta5 pregnenolone. Late appearance of the first episode of dehydration, particularly intense cutaneous pigmentation and statural growth and bone maturation both unaffected, are some particular traits of this patient.