Presence of H-Y antigen and testis in 46, XX true hermaphroditism, evidence for Y-chromosomal function.

Endocrinologic and serologic studies of a 2-year-old child with the chromosomal complement 46,XX and ambiguous genitalia suggested the preoperative diagnosis of true hermaphroditism. Urinary and serum androgen production in response to human chorionic gonadotrophin was in the range expected for normal males, implying presence of cryptic testicular tissue. Moreover, detection of H-Y antigen, a cell surface component associated with testicular differentiation and coded or regulated by a Y-chromosomal gene, indicated presence of Y-chromosomal material. The diagnosis of true hermaphroditism was confirmed at surgery. Assuming a constant association of H-Y antigen and testicular differentiation is established, human H-Y serology may be an important adjunct to the endocrinologic evaluation of intersex patients. Our studies support the interpretation that a Y-chromosomal translocation too small for cytologic detection accounts for testicular differentiation in 46,XX true hermaphroditism. Expression of H-Y antigen remained positive after castration.