Pseudohermaphroditism due to XY gonadal absence syndrome.

Abstract

A 21 yr old phenotypic female with a 46,XY chromosome complement and gonadal absence was studied. Basal levels of plasma immunoreactive luteinizing hormone (LH), follicle stimulating hormone (FSH), testosterone, and estradiol were measured. Pituitary sensitivity and reserve was evaluated by the exogenous administration of synthetic luteinizing hormone-releasing hormone. The episodic release of gonadotrophins was assessed by measuring plasma LH and FSH in plasma samples obtained at 20-min intervals for a 4-h period. Endocrine gonadal function was evaluated by a stimulation test with human chorionic gonadotrophin (HCG) for 3 days. The results showed persistently raised plasma levels of both LH and FSH; a pulsatile pattern of release of both gonadotrophins and a normal pituitary response to the synthetic hypothalamic decapeptide; and extremely low levels of circulating testosterone and estradiol with a lack of response to the HCG stimulus. A careful exploratory laparotomy revealed absence of uterus, Fallopian tubes, the Muellerian portion of the vagina, and gonads. No Wolffian derivatives were found. A dissociation of testosterone and Jost substance effects during early sexual development may explain the findings in this unusual abnormality. The term XY gonadal absence syndrome including 5 types of variants to designate this condition is proposed.