Presence of H-Y antigen in female patients with sex-chromosome mosaics and absence of testicular tissue.

H-Y antigen was tested in five women with sex chromosome mosaicism and gonadal streaks. Three patients had a 45,X/46,XY or 46,X,der(Y) and two a 45,X/46,X, der(X) chromosome constitution. All patients were H-Y antigen positive. Lack of testis differentiation in these women may be explained by subthreshold expression of H-Y antigen, different H-Y antigen molecules, and/or different tissue distribution of the chromosome mosaicism.