H-Y antigen in transsexuality, and how to explain testis differentiation in H-Y antigen-negative males and ovary differentiation in H-Y antigen-positive females.
H-Y antigen was determined in eight transsexual patients. Two of the four male-to-female transsexual patients typed as H-Y antigen-negative, while the other two typed as expected from their phenotypic and gonadal sex, namely H-Y antigen-positive. Of the four female-to-male transsexual patients, three typed as H-Y antigen-positive and one was H-Y antigen-negative, as expected. The presence of normal testes in H-Y antigen-negative males is assumed to result from a mutation of nucleotide sequences of the H-Y structural gene for antigenic determinants. Thus, an H-Y is produced with normal receptor-binding activity which can sustain the testis determination of the bipotent gonadal anlage. In the case of H-Y antigen-positive females with normal ovaries a deletion of the autosomally located H-Y structural gene is assumed. This deletion should affect sequences for repressor-binding (as was suggested for H-Y antigen-positive XX-males) and for receptor-binding activity of the H-Y antigen molecule. The resulting H-Y antigen is unable to bind to the gonadal receptor of the bipotent gonadal anlage. Thus an ovary is determined. The relevance of H-Y antigen for the aetiology of transsexualism is discussed.
D002872:Chromosome Deletion; D005260:Female; D006182:H-Y Antigen / Q000235:genetics / Q000276:immunology*; D006801:Humans; D008297:Male; D008957:Models, Genetic; D009024:Morphogenesis; D010053:Ovary / Q000196:embryology; D011946:Receptors, Antigen / Q000235:genetics / Q000378:metabolism; D012729:Sex Chromosome Aberrations / Q000276:immunology; D012732:Sex Determination Analysis; D013737:Testis / Q000196:embryology; D014189:Transsexualism / Q000235:genetics / Q000276:immunology*; D014960:X Chromosome
D006182:H-Y Antigen; C028507:H-Y antigen receptor; D011946:Receptors, Antigen