The Use of Whole Exome Sequencing in a Cohort of Transgender Individuals to Identify Rare Genetic Variants

Identification of rare genetic variants in the PCDH genetic family in a cohort of transgender women

OBJECTIVE

To study the identification of rare genetic variants in the PCDH genetic family in a cohort of transgender women (TGW) and their potential role in gender identity.

DESIGN

Exome sequencing and functional ontology analysis.

SETTING

Outpatient gender health and reproductive endocrinology clinics.

PATIENT(S)

A total of 24 TGW and 22 cisgender men (CM).

INTERVENTION(S)

Exome sequencing followed by variant confirmation through Sanger sequencing and functional classification analysis using the Database for Annotation, Visualization, and Integrated Discovery tool.

MAIN OUTCOME MEASURE(S)

Identification of rare, functionally significant genetic variants in the PCDH gene family and their prevalence in TGW compared with CM.

RESULT(S)

Exome sequencing revealed 38,524 genetic variants, of which 2,441 were rare and predicted to be functionally significant. The Database for Annotation, Visualization, and Integrated Discovery analysis demonstrated a statistically enriched functional group, "homophilic cell adhesion via plasma membrane adhesion molecules," containing 55 genes, including 18 PCDH gene family members. A total of 37 rare variants in 21 PCDH genes were identified, with 36 confirmed using Sanger sequencing. A statistically significant increase in these variants was observed in TGW compared with CM (Z = 2.08905).

CONCLUSION(S)

Transgender women exhibited a greater than threefold increase in functionally significant PCDH gene variants compared with CM. These findings suggest that the PCDH family may play a role in the genetic pathways associated with gender identity in TGW.

Queering genomics: How cisnormativity undermines genomic science

Over the past century, genetics and genomics ("genomics") have contributed significantly to our knowledge of human biology and disease. Genomics has also bolstered inaccurate and harmful arguments about "essential" differences between socially defined groups. These purported differences have reinforced class hierarchies and justified the mistreatment of groups such as Black people, Indigenous people, and other people of color and/or people with disabilities. With this history in mind, we explore how genomics is used to reinforce scientifically unsound understandings of the relationship between two fundamental aspects of the human experience: sex and gender. We argue that imprecise, inaccurate practices for collecting data and conducting genomic research have adversely influenced genomic science and can contribute to the stigmatization of people whose sex and/or gender challenge binary expectations. The results have been to preclude transgender and intersex people from accessing high-quality, evidence-based healthcare and to hinder their participation in scientifically sound research. In this perspective, we use the lens of queer theory to render this situation more visible. First, we highlight the theoretical contributions queer theory can make to genomic science. Second, we examine practices in research and clinical genomics that exclude and stigmatize transgender and intersex people. Third, we highlight the ways that many current genomic research practices generate false conclusions that are used to support unjust public policies. We conclude by recommending ways that clinicians and researchers can-and should-harness the scientific, social, and cultural power of genomics to advance knowledge and improve lives across the spectra of sex and gender.

Giftedness and atypical sexual differentiation: enhanced perceptual functioning through estrogen deficiency instead of androgen excess

Syndromic autism spectrum conditions (ASC), such as Klinefelter syndrome, also manifest hypogonadism. Compared to the popular Extreme Male Brain theory, the Enhanced Perceptual Functioning model explains the connection between ASC, savant traits, and giftedness more seamlessly, and their co-emergence with atypical sexual differentiation. Overexcitability of primary sensory inputs generates a relative enhancement of local to global processing of stimuli, hindering the abstraction of communication signals, in contrast to the extraordinary local information processing skills in some individuals. Weaker inhibitory function through gamma-aminobutyric acid type A (GABAA) receptors and the atypicality of synapse formation lead to this difference, and the formation of unique neural circuits that process external information. Additionally, deficiency in monitoring inner sensory information leads to alexithymia (inability to distinguish one's own emotions), which can be caused by hypoactivity of estrogen and oxytocin in the interoceptive neural circuits, comprising the anterior insular and cingulate gyri. These areas are also part of the Salience Network, which switches between the Central Executive Network for external tasks and the Default Mode Network for self-referential mind wandering. Exploring the possibility that estrogen deficiency since early development interrupts GABA shift, causing sensory processing atypicality, it helps to evaluate the co-occurrence of ASC with attention deficit hyperactivity disorder, dyslexia, and schizophrenia based on phenotypic and physiological bases. It also provides clues for understanding the common underpinnings of these neurodevelopmental disorders and gifted populations.

Polygenic Scores Clarify the Relationship Between Mental Health and Gender Diversity

Background

Gender-diverse individuals are at increased risk for mental health problems, but it is unclear whether this is due to shared environmental or genetic factors.

Methods

In two SPARK samples, we tested for associations of 16 polygenic scores (PGSs) with quantitative measures of gender diversity and mental health. In study 1, 639 independent adults (59% autistic) reported their mental health with the Adult Self-Report and their gender diversity with the Gender Self-Report (GSR). The GSR has 2 dimensions: binary (degree of identification with the gender opposite that implied by sex designated at birth) and nonbinary (degree of identification with a gender that is neither male nor female). In study 2 (N = 5165), we used a categorical measure of gender identity.

Results

In study 1, neuropsychiatric PGSs were positively associated with Adult Self-Report scores: externalizing was positively associated with the attention-deficit/hyperactivity disorder PGS (β = 0.10 [0.03-0.17]), and internalizing was positively associated with the PGSs for depression (β = 0.07 [0-0.14]) and neuroticism (β = 0.10 [0.03-0.17]). Interestingly, GSR scores were not significantly associated with any neuropsychiatric PGS. However, GSR nonbinary was positively associated with the cognitive performance PGS (β = 0.11 [0.05-0.18]), with the effect size comparable in magnitude to the associations of the neuropsychiatric PGSs with the Adult Self-Report. Additionally, GSR binary was positively associated with the nonheterosexual sexual behavior PGS (β = 0.07 [0-0.14]). In study 2, the cognitive performance PGS effect replicated; transgender and nonbinary individuals had higher PGSs (t316 = 4.16).

Conclusions

We showed that while gender diversity is phenotypically positively associated with mental health problems, the strongest PGS associations with gender diversity were with the cognitive performance PGS, not the neuropsychiatric PGSs.

Gender-affirming hormone therapy, mental health, and surgical considerations for aging transgender and gender diverse adults

As the transgender and gender diverse (TGD) population ages, more transfeminine and transmasculine individuals present to clinic to initiate or continue their gender-affirming care at older ages. Currently available guidelines on gender-affirming care are excellent resources for the provision of gender-affirming hormone therapy (GAHT), primary care, surgery, and mental health care but are limited in their scope as to whether recommendations require tailoring to older TGD adults. Data that inform guideline-recommended management considerations, while informative and increasingly evidence-based, mainly come from studies of younger TGD populations. Whether results from these studies, and therefore recommendations, can or should be extrapolated to aging TGD adults remains to be determined. In this perspective review, we acknowledge the lack of data in older TGD adults and discuss considerations for evaluating cardiovascular disease, hormone-sensitive cancers, bone health and cognitive health, gender-affirming surgery, and mental health in the older TGD population on GAHT.

"It's completely erasure": A Qualitative Exploration of Experiences of Transgender, Nonbinary, Gender Nonconforming, and Questioning Students in Biology Courses

Biology is the study of the diversity of life, which includes diversity in sex, gender, and sexual, romantic, and related orientations. However, a small body of literature suggests that undergraduate biology courses focus on only a narrow representation of this diversity (binary sexes, heterosexual orientations, etc.). In this study, we interviewed students with queer genders to understand the messages about sex, gender, and orientation they encountered in biology and the impact of these messages on them. We found five overarching themes in these interviews. Students described two narratives about sex, gender, and orientation in their biology classes that made biology implicitly exclusionary. These narratives harmed students by impacting their sense of belonging, career preparation, and interest in biology content. However, students employed a range of resilience strategies to resist these harms. Finally, students described the currently unrealized potential for biology and biology courses to validate queer identities by representing the diversity in sex and orientation in biology. We provide teaching suggestions derived from student interviews for making biology more queer-inclusive.

Adolescent gender diversity: sociodemographic correlates and mental health outcomes in the general population

BACKGROUND

Gender diversity in young adolescents is understudied outside of referral clinics. We investigated gender diversity in an urban, ethnically diverse sample of adolescents from the general population and examined predictors and associated mental health outcomes.

METHODS

The study was embedded in Generation R, a population-based cohort of children born between 2002 and 2006 in Rotterdam, the Netherlands (n = 5727). At ages 9-11 and 13-15 years, adolescents and/or their parents responded to two questions addressing children's contentedness with their assigned gender, whether they (a) 'wished to be the opposite sex' and (b) 'would rather be treated as someone from the opposite sex'. We defined 'gender-variant experience' when either the parent or child responded with 'somewhat or sometimes true' or 'very or often true'. Mental health was assessed at 13-15 years, using the Achenbach System of Empirically Based Assessment.

RESULTS

Less than 1% of the parents reported that their child had gender-variant experience, with poor stability between 9-11 and 13-15 years. In contrast, 4% of children reported gender-variant experience at 13-15 years. Adolescents who were assigned female at birth reported more gender-variant experience than those assigned male. Parents with low/medium educational levels reported more gender-variant experience in their children than those with higher education. There were positive associations between gender-variant experience and symptoms of anxiety, depression, somatic complaints, rule-breaking, and aggressive behavior as well as attention, social, and thought problems. Similar associations were observed for autistic traits, independent of other mental difficulties. These associations did not differ by assigned sex at birth.

CONCLUSIONS

Within this population-based study, adolescents assigned females were more likely to have gender-variant experience than males. Our data suggest that parents may not be aware of gender diversity feelings in their adolescents. Associations between gender diversity and mental health symptoms were present in adolescents.

Concordance for Gender Dysphoria in Genetic Female Monozygotic (Identical) Triplets

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 (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.

Transgender and gender-diverse (TGD) individuals' perspectives on research seeking genetic variants associated with TGD identities: a qualitative study

Recent genetic research has explored how genetic variants may contribute to gender dysphoria and transgender and gender-diverse (TGD) identities. When investigating communities that have been marginalized, it is important for researchers to incorporate perspectives of the communities the research is targeting. Therefore, investigators should incorporate the TGD community's opinions into this research to mitigate potential ethical issues, given the history of pathologization of TGD identities and utilization of genetics for eugenics. The aim of this study was to understand the perspectives of TGD individuals about trans-associated genetic research (TAGR). Eighteen semi-structured interviews were conducted with members of the TGD community to explore how TGD individuals view TAGR. Through inductive content analysis, five major themes were emergent: (1) TAGR could affect self-perception of identity; (2) TAGR could affect external views of TGD people; (3) TAGR could affect access to gender-affirming services; (4) TAGR could contribute to the pathologization and elimination of TGD identities; and (5) researchers should consult TGD community members and consider ethical concerns before conducting research. Participants highlighted concerns about TAGR being used as a tool for discrimination. Those who identified potential advantages of TAGR gave warning that TAGR would be unlikely to solely have positive effects. It is important for genetic researchers to prioritize the perspectives and concerns of TGD people highlighted in this study. Research about the TGD community needs to include TGD individuals as core members of the research team. Moreover, due to the serious ethical issues outlined in this study, TAGR should be reconsidered altogether.

Challenges in the care of transgender and gender-diverse youth: an endocrinologist's view

An increasing number of transgender and gender-diverse (TGD) youth (early pubertal through to late adolescent, typically 9-10 through to 18 years of age) are seeking medical services to bring their physical sex characteristics into alignment with their gender identity - their inner sense of self as male or female or somewhere on the gender spectrum. Compelling research has demonstrated the clear mental health - even life-saving - benefits of gender-affirming care, but current clinical practice guidelines and standards of care are based on only several short-term and a few medium-term outcomes studies complemented by expert opinion. Nevertheless, although the relative paucity of outcomes data raises concerns, the stance of not intervening until more is known is not a neutral option, and large observational studies evaluating current models of care are necessary and are now underway. This Review highlights key advances in our understanding of transgender and gender-diverse youth, the challenges of providing gender-affirming care, gaps in knowledge and priorities for research.

Childhood transgenderity under the perspective of elementary school teachers

OBJECTIVE

to analyze teachers' conceptions about transgenderity in childhood and to identify the possibilities and limits of working with these children in the school context.

METHOD

a qualitative research study, carried out with 23 teachers from two municipal elementary schools. Semi-structured interviews were used to produce empirical material. As an analytical resource, the content analysis technique, thematic modality, was used.

RESULTS

six thematic categories emerged in the set of empirical material: There is transgenderity in childhood; The construction of gender identity and roles in childhood; The experience of trans children in the school context; Trans children: How to deal with?; Discussing the differences in the classroom: Is this the way?; and Dilemmas of school and family interaction. It was found that the gender dichotomy is reinforced in the classroom, causing tensions and stereotyped divisions for male and female roles. Various forms of violence have been reproduced by classmates and teachers, who, due to lack of knowledge or to unpreparedness, reinforce concepts and attitudes that lead to the maintenance of exclusion.

CONCLUSION

the schools find it difficult to promote the inclusion of trans children. It is necessary to create strategies aimed at raising awareness and training the professionals who make up the school environment, especially teachers in the initial grades.

Genetics of agenesis/hypoplasia of the uterus and vagina: narrowing down the number of candidate genes for Mayer-Rokitansky-Küster-Hauser Syndrome

PURPOSE

Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome consists of congenital absence of the uterus and vagina and is often associated with renal, skeletal, cardiac, and auditory defects. The genetic basis is largely unknown except for rare variants in several genes. Many candidate genes have been suggested by mouse models and human studies. The purpose of this study was to narrow down the number of candidate genes.

METHODS

Whole exome sequencing was performed on 111 unrelated individuals with MRKH; variant analysis focused on 72 genes suggested by mouse models, human studies of physiological candidates, or located near translocation breakpoints in t(3;16). Candidate variants (CV) predicted to be deleterious were confirmed by Sanger sequencing.

RESULTS

Sanger sequencing verified 54 heterozygous CV from genes identified through mouse (13 CV in 6 genes), human (22 CV in seven genes), and translocation breakpoint (19 CV in 11 genes) studies. Twelve patients had ≥ 2 CVs, including four patients with two variants in the same gene. One likely digenic combination of LAMC1 and MMP14 was identified.

CONCLUSION

We narrowed 72 candidate genes to 10 genes that appear more likely implicated. These candidate genes will require further investigation to elucidate their role in the development of MRKH.

Bone Development in Transgender Adolescents Treated With GnRH Analogues and Subsequent Gender-Affirming Hormones

CONTEXT

Hormonal interventions in adolescents with gender dysphoria may have adverse effects, such as reduced bone mineral accrual.

OBJECTIVE

To describe bone mass development in adolescents with gender dysphoria treated with gonadotropin-releasing hormone analogues (GnRHa), subsequently combined with gender-affirming hormones.

DESIGN

Observational prospective study.

SUBJECTS

51 transgirls and 70 transboys receiving GnRHa and 36 transgirls and 42 transboys receiving GnRHa and gender-affirming hormones, subdivided into early- and late-pubertal groups.

MAIN OUTCOME MEASURES

Bone mineral apparent density (BMAD), age- and sex-specific BMAD z-scores, and serum bone markers.

RESULTS

At the start of GnRHa treatment, mean areal bone mineral density (aBMD) and BMAD values were within the normal range in all groups. In transgirls, the mean z-scores were well below the population mean. During 2 years of GnRHa treatment, BMAD stabilized or showed a small decrease, whereas z-scores decreased in all groups. During 3 years of combined administration of GnRHa and gender-affirming hormones, a significant increase of BMAD was found. Z-scores normalized in transboys but remained below zero in transgirls. In transgirls and early pubertal transboys, all bone markers decreased during GnRHa treatment.

CONCLUSIONS

BMAD z-scores decreased during GnRHa treatment and increased during gender-affirming hormone treatment. Transboys had normal z-scores at baseline and at the end of the study. However, transgirls had relatively low z-scores, both at baseline and after 3 years of estrogen treatment. It is currently unclear whether this results in adverse outcomes, such as increased fracture risk, in transgirls as they grow older.

Case Report of Transgender Patient with Gonadotropic Dysfunction Secondary to Craniopharyngioma: Toward Improving Understanding of Biopsychosocial Dynamics of Gender Identity in Neurosurgical Care

BACKGROUND

There is a paucity of information in the literature linking possible neuroendocrinologic repercussions of anterior pituitary insufficiency from tumor-associated mass effect with gender identity in transindividuals. The authors present the case of a 26-year-old transgender woman who was found to have a sellar/suprasellar neoplasm after reporting loss of vision in a bitemporal distribution.

CASE DESCRIPTION

Magnetic resonance imaging demonstrated a 2.6-cm complex cystic and solid sellar/suprasellar mass, suggestive of craniopharyngioma, intimately associated with the pituitary stalk. Importantly, this radiographic diagnosis was made 2 years following the initiation of gender-affirming hormone therapy (HT). Laboratory testing following radiographic diagnosis demonstrated evidence of diffuse anterior pituitary insufficiency with decreased morning cortisol, free thyroxine, insulin-like growth factor-1, and testosterone. Following optimization with the endocrinology team, the patient was taken to the operating room for expanded endonasal resection of tumor with lumbar drain insertion and nasoseptal flap coverage. Gross total resection was achieved with marked improvement in vision noted following surgery. The patient continued her HT following surgery.

CONCLUSIONS

In hindsight, the neuroendocrinologic manifestations of the craniopharyngioma may have influenced distressing pubertal experiences that distanced her from her assigned male sex, as well as the desired effects of feminization HT in this patient, ultimately delaying her presentation to the neurosurgery service and diagnosis of craniopharyngioma. As the first report of the neurosurgical evaluation and treatment of a transgender patient with anterior pituitary insufficiency secondary to craniopharyngioma, this case examines the biopsychosocial interplay between the development of gender identity and the neuroendocrinologic manifestations of craniopharyngioma.