[Transsexualism and the H-Y antigen]

First reports about incongruous H-Y antigen status in male-to-female and female-to-male transsexuals have been published by us in 1979. Meanwhile H-Y antigen expression was analyzed with the cytotoxicity assay of Goldberg et al. in 61 transsexuals. In 55 cases H-Y antigen status was found discordant with the anatomical, chromosomal and hormonal sex and corresponded to the gender identity of transsexuals. The relative frequency was 0,91. In 33 male-to-female transsexuals 29 were H-Y negative, one was intermediate, three were H-Y positive. In 28 female-to-male transsexuals 25 were H-Y positive, one was intermediate, two were H-Y negative. The new findings of an incongruous H-Y antigen status in genuine transsexuals may lead to new considerations about the pathogenesis of the disease and about the function of H-Y antigen.