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Discordant transsexualism in male monozygotic twins: neuroanatomical and psychological differences
Tahiana Signorini Andreazza1, Angelo Brandelli Costa, Raffael Massuda
1Gender Identity Disorder Program, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil, tahianasa@yahoo.com.br.
Abstract:
One monozygotic male twin pair discordant for transsexualism is described. Both twins were interviewed and tested with the Wechsler Adult Intelligence Scale battery for cognitive functions and they underwent magnetic resonance imaging to measure the volumes of specific cerebral structures. Interviews with the twins and their mother indicated no unusual medical or life history events that could have had a causal role in the emergence of the disorder. Both cognitive function testing and neuroimaging detected differences between the twins that could be related to unexplained epigenetic effects and exogenous hormone usage.
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