“Concordance for Gender Dysphoria in Genetic Female Monozygotic (Identical) Triplets”, 2022-08-31 (; backlinks):
The biopsychosocial etiology of gender dysphoria is poorly understood, but current thought suggests a complex interaction of genetic, hormonal, environmental, and differences in brain development and physiology. Twin studies have implicated a genetic role in the formation of gender identity. Congruence for gender dysphoria is more common among monozygotic twins compared to dizygotic twins.
We present a case of monozygotic (ie. identical) triplets who have each transitioned from female to male under the care of a university transgender health service. Each triplet experienced gender dysphoria from childhood and has undergone transitional endocrine care and various aspects of gender-affirming surgery.
Although a pure genetic or biological component cannot be attributed as a cause of their gender dysphoria with absolute certainty since the triplets were raised together, this unusual case of gender dysphoria among a set of monozygotic triplets adds support for a heritable role in gender identity formation.
[Keywords: transgender, triplets, monozygotic, gender dysphoria, gender identity]
…Due to the triplet’s age at presentation [23–27], birth records were no longer available. They were born prematurely at ~32 weeks, assigned female gender, and raised from birth by their maternal grandparents as the biological mother was unwilling to care for the triplets. The grandparents were involved during prenatal care and provided background pregnancy and early childhood developmental history. Monozygosity was established by prenatal ultrasound and placental examination (ie. monochorionic, triamniotic placenta) according to the grandmother.
Each had normal female external genitalia at birth. No developmental disorders were encountered in childhood, and all motor, social, and language milestones were met on time. Each had attained some college education. Initially, the triplets were raised female by their maternal grandparents, and each of the triplets rated his childhood environment favorably aside from gender dysphoria. Sexual and physical abuse history was absent.
According to the triplets, each had self-identified as a “boy” by the age of 8, assumed masculine names, and dressed accordingly, a decision supported by the grandparents. Each denied coercive persuasion from co-siblings. Prior to androgenizing therapy, two had undergone gender-affirming mastectomies at ages 22 and 23, and the third plans to do so. The decision to undergo mastectomies (performed in another US state) prior to androgenizing treatment was due to perceived lack of affordable and transgender-friendly care locally. The last triplet to present for endocrine care stated he was more fluid in his identity than his brothers, and hence, delayed his decision to initiate transitional care.
All 3 have been treated for anxiety (with co-morbid gender dysphoria) beginning in late adolescence with clinical response to sertraline 50 mg as an adjunct to psychotherapy. All continue in psychotherapy with their referring psychologist and are currently functioning well professionally and socially. No other medical comorbidities are present.
At the time of the most recent follow-up, all 3 brothers denied prior sexual activity, and each states that his sexual identity is asexual although arousal patterns are gynephilic. They currently live together but are employed individually. Androgen requirements have been similar for successful virilization.
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