Transsexualism in female monozygotic twins: a case report

Objective: A case report is presented of a gender identity disorder involvi ng a pair of female monozygotic twins who requested sex reassignment. As fa r as we know, this case is the first in psychiatric literature and supports a genetic aetiology of this disorder. Clinical picture: The patients were two 18-year-old female monozygotic twin s who had showed symptoms of transsexualism since early childhood. They had no other physical or psychiatric disorder except borderline mental functio ning. Treatment: The patients were referred for sex reassignment. Outcome: They were lost to follow up after initial evaluation. Conclusion: In addition to other possible (yet not confirmed) causes of tra nssexualism, a genetic basis for this disorder is suggested by this case.