Unidad de Identidad de Género, Instituto Clínic de Neurociencias, Servicio de Psiquiatría, Hospital Clínic, Universidad de Barcelona, Villarroel 170, 08036, Barcelona, Spain.
Arch Sex Behav. 2010 Apr;39(2):546-52. doi: 10.1007/s10508-009-9524-4. Epub 2009 Jul 29.
Familial studies and reports of co-occurrence of gender identity disorder (GID) within a family may help to clarify the question of whether transsexualism is a familial phenomenon. In a sample of 995 consecutive transsexual probands (677 male-to-female [MF] and 318 female-to-male [FM]), we report 12 pairs of transsexual non-twin siblings (nine pairs of MF siblings, two pairs of MF-FM siblings, and one pair of FM siblings). The present study doubles the number of case reports of co-occurrence of transsexualism in non-twin siblings available in the literature. According to our data, the probability that a sibling of a transsexual will also be transsexual was 4.48 times higher for siblings of MF than for siblings of FM transsexual probands, and 3.88 times higher for the brothers than for the sisters of transsexual probands. Moreover, the prevalence of transsexualism in siblings of transsexuals (1/211 siblings) was much higher than the range expected according to the prevalence data of transsexualism in Spain. The study suggests that siblings of transsexuals may have a higher risk of being transsexual than the general population, and that the risk is higher for brothers than sisters of transsexuals, and for siblings of MF than FM transsexuals. Nevertheless, the risk is low.
家族研究以及跨性别身份障碍（GID）在家族中同时出现的报告有助于阐明易性症是否为家族现象。在 995 名连续的跨性别者样本中（677 名男变女[MF]和 318 名女变男[FM]），我们报告了 12 对跨性别非双胞胎兄弟姐妹（9 对 MF 兄弟姐妹，2 对 MF-FM 兄弟姐妹，和 1 对 FM 兄弟姐妹）。本研究将文献中关于非双胞胎跨性别者同时出现的案例报告数量增加了一倍。根据我们的数据，MF 跨性别者的兄弟姐妹成为跨性别者的可能性是 FM 跨性别者兄弟姐妹的 4.48 倍，是跨性别者兄弟姐妹中兄弟的可能性是姐妹的 3.88 倍。此外，跨性别者兄弟姐妹中跨性别者的患病率（1/211 个兄弟姐妹）远高于西班牙跨性别者患病率数据所预期的范围。该研究表明，跨性别者的兄弟姐妹成为跨性别者的风险可能高于普通人群，而且对于跨性别者的兄弟姐妹来说，这种风险对于男性比女性更高，对于 MF 跨性别者的兄弟姐妹比 FM 跨性别者的兄弟姐妹更高。然而，这种风险是低的。
