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

• Published in: Human genetics 1980-01, Vol.55 (3), p.315-319
• Main Authors: Engel, W, Pfäfflin, F, Wiedeking, C
• Format: Article
• Language: English
• Subjects: Chromosome Deletion; Female; H-Y Antigen - genetics; H-Y Antigen - immunology; Humans; Male; Models, Genetic; Morphogenesis; Ovary - embryology; Receptors, Antigen - genetics; Receptors, Antigen - metabolism; Sex Chromosome Aberrations - immunology; Sex Determination Analysis; Testis - embryology; Transsexualism - genetics; Transsexualism - immunology; X Chromosome
• ISSN: 0340-6717; 1432-1203
• DOI: 10.1007/BF00290210

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.