A study of consanguinity between the parents of transsexuals.

During recent years there have been published a number of reports of more than one case of transsexualism or other sexual pathology occurring within the same family. As long as the aetiology of transsexualism remains unknown the authors consider that a possible effect of recessive genes cannot be definitely excluded. To ascertain whether transsexual patients are born of cousin marriages to a greater extent than expected the authors have fully investigated family relationships for 61 known cases of transsexualism. No case of cousin marriage was disclosed.