No relationship between prenatal androgen exposure and autistic traits: convergent evidence from studies of children with congenital adrenal hyperplasia and of amniotic testosterone concentrations in typically developing children

Maternal Steroid Hormone Levels in Early Pregnancy and Autism in the Offspring: A Population-Based, Nested Case-Control Study

BACKGROUND

A role for prenatal steroid hormones in the etiology of autism has been proposed, but evidence is conflicting.

METHODS

Here, we examined serum levels of maternal estradiol, testosterone, 17-hydroxyprogesterone (OHP), and cortisol from the first trimester of gestation (mean = 10.1 weeks) in relation to the odds of diagnosed autism with and without co-occurring intellectual disability (ID) in the offspring (n = 118 autism with ID, n = 249 autism without ID, n = 477 control). Levels of maternal hormones were measured using highly sensitive liquid chromatography tandem mass spectrometry, standardized according to gestational timing of sample collection, and analyzed with restricted cubic spline logistic regression models adjusting for child's sex and maternal health, demographic, and socioeconomic factors.

RESULTS

We observed significant nonlinear associations between maternal estradiol, 17-OHP, and cortisol with autism, which varied with the presence of co-occurring ID. Compared to mean levels, lower levels of estradiol were associated with higher odds of autism with ID (odds ratio for concentrations 1 SD below the mean = 1.66; 95% CI, 1.24-2.11), while higher cortisol levels were associated with lower odds (odds ratio for 1 SD above the mean = 0.55; 95% CI, 0.36-0.88). In contrast, higher 17-OHP was associated with increased odds of autism without ID (odds ratio for 1 SD above the mean = 1.49; 95% CI, 1.11-1.99). We observed no evidence for interaction with sex of the child.

CONCLUSIONS

These findings support the notion that the maternal steroid hormonal environment in early pregnancy may contribute to autism, but also emphasize the complex relationship between early-life steroid exposure and autism.

Endocrine, cardiac and neuropsychological aspects of adult congenital adrenal hyperplasia

OBJECTIVE

To investigate the metabolic, cardiovascular, and neuropsychological phenotype, quality of life (QoL), and hormonal regulation in individuals with congenital adrenal hyperplasia (CAH), a group of autosomal recessive disorders characterized by impaired synthesis of cortisol in the adrenal cortex and, if untreated compensatory hyperandrogenism. CAH is associated with an increased cardiovascular and metabolic morbidity, possibly due to overtreatment with glucocorticoids, leading to weight gain, insulin resistance, and metabolic syndrome.

DESIGN, PARTICIPANTS, MEASUREMENTS

Thirty-seven individuals with CAH and 33 age- and sex-matched controls were evaluated at a single centre at Aarhus University Hospital with echocardiography, electrocardiogram, 24-h blood pressure, biochemistry, anthropometrics, and autism spectrum, anxiety, depression, personality, cognitive failures, and QoL were assessed using questionnaires.

RESULTS

CAH individuals had lower height than controls (170.5 vs. 182.9 cm in males and 160.2 vs. 170.1 cm in females, p < 0.01). Compared with female controls, females with CAH had higher haemoglobin (8.8 vs. 8.2 mmol/L, p = 0.003) and BMI (29.7 vs. 25.5 kg/m2, p = 0.006), reduced insulin sensitivity (HOMA-IR): 2.7 vs. 1.9, p = 0.018), prolonged E-wave deceleration time (193 vs. 174 cm, p = 0.015), and E/é ratios (5.4 vs. 4.5, p = 0.017), and lower self-reported QoL. Males with CAH had more cognitive complaints (p = 0.034) and higher autistic scores (19.9 vs. 14.9; p = 0.068) compared with male controls. More individuals with CAH than controls reported writing problems.

CONCLUSION

A sex-specific comorbidity profile is evident in CAH, with females presenting with decreased metabolic and overall self-reported health, whereas males with CAH presented with increased cognitive complaints and autistic traits.

Prenatal androgen exposure and sex-typical play behaviour: A meta-analysis of classic congenital adrenal hyperplasia studies

Thousands of non-human mammal experiments have demonstrated that early androgen exposure exerts long-lasting effects on neurobehavioural sexual differentiation. In humans, females with classic congenital adrenal hyperplasia (CAH) are exposed to unusually high concentrations of androgens prenatally, whereas prenatal concentrations of androgens in males with CAH are largely normal. The current meta-analysis included 20 independent samples and employed multi-level meta-analytic models. Consistently across all 7 male-typical and female-typical play outcomes, in the expected directions, the present study found significant and large average differences between control males and control females (gs = 0.83-2.78) as well as between females with CAH and control females (gs = 0.95-1.08), but differences between males with CAH and control males were mostly negligible and were non-significant for 6 of the 7 outcomes (gs = 0.04-0.27). These meta-analytic findings suggest that prenatal androgen exposure masculinises and defeminises play behaviour in humans. Broader implications in relation to sex chromosomes, brain development, oestrogens, socio-cognitive influences, other aspects of sex-related behavioural development, and gender nonconformity are discussed.

Excess neonatal testosterone causes male-specific social and fear memory deficits in wild-type mice

Neurodevelopmental disorders (ND) disproportionately affect males compared to females, and Autism Spectrum Disorder (ASD) in particular exhibits a 4:1 male bias. The biological mechanisms of this female protection or male susceptibility have not been identified. There is some evidence to suggest that fetal/neonatal gonadal hormones, which play pivotal roles in many aspects of development, may contribute. Here, we investigate the role of testosterone administration during a critical period of development, and its effects on social approach and fear learning in C57BL/6J wildtype mice. Male, but not female mice treated with testosterone on the day of birth (PN0) exhibited deficits in both social behavior and contextual fear conditioning, whereas mice treated with the same dose of testosterone on postnatal day 18 (PN18) did not display such impairments. Testosterone administration did not induce anxiogenic effects or lead to changes in body weight compared to the vehicle-treated group. These impairmeants are relevant to ND and may help identify novel treatment targets.

Sex differences in placenta-derived markers and later autistic traits in children

Autism is more prevalent in males and males on average score higher on measures of autistic traits. Placental function is affected significantly by the sex of the fetus. It is unclear if sex differences in placental function are associated with sex differences in the occurrence of autistic traits postnatally. To assess this, concentrations of angiogenesis-related markers, placental growth factor (PlGF) and soluble fms-like tyrosine kinase (sFlt-1) were assessed in maternal plasma of expectant women in the late 1^st (mean= 13.5 [SD = 2.0] weeks gestation) and 2^nd trimesters (mean=20.6 [SD = 1.2] weeks gestation), as part of the Generation R Study, Rotterdam, the Netherlands. Subsequent assessment of autistic traits in the offspring at age 6 was performed with the 18-item version of the Social Responsiveness Scale (SRS). Associations of placental protein concentrations with autistic traits were tested in sex-stratified and cohort-wide regression models. Cases with pregnancy complications or a later autism diagnosis (n = 64) were also assessed for differences in placenta-derived markers. sFlt-1 levels were significantly lower in males in both trimesters but showed no association with autistic traits. PlGF was significantly lower in male pregnancies in the 1^st trimester, and significantly higher in the 2^nd trimester, compared to female pregnancies. Higher PlGF levels in the 2^nd trimester and the rate of PlGF increase were both associated with the occurrence of higher autistic traits (PlGF-2^nd: n = 3469,b = 0.24 [SE = 0.11], p = 0.03) in both unadjusted and adjusted linear regression models that controlled for age, sex, placental weight and maternal characteristics. Mediation analyses showed that higher autistic traits in males compared to females were partly explained by higher PlGF or a faster rate of PlGF increase in the second trimester (PlGF-2^nd: n = 3469, ACME: b = 0.005, [SE = 0.002], p = 0.004). In conclusion, higher PlGF levels in the 2^nd trimester and a higher rate of PlGF increase are associated with both being male, and with a higher number of autistic traits in the general population.

Mini-puberty testosterone and infant autistic traits

Background

Levels of steroid hormones in the first three months of life, a period referred to as 'mini-puberty', are one of the earliest physiological differences between typical males and females postnatally. Autistic traits also show consistent typical sex differences in later infancy, after the 18th month of life. Previous studies have shown prenatal testosterone is associated with later levels of autistic traits. Studies testing if postnatal testosterone levels are associated with autistic traits have reported null results. No studies to date have investigated mini-puberty longitudinally or tested for interactions with baseline sex differences or familial likelihood of autism.

Methods

The 'Cambridge Human Imaging and Longitudinal Development Study' (CHILD) is a prospective enriched cohort study in Cambridge, UK. It includes physiological measurements in early infancy, as well as neurodevelopmental follow-ups over the first two years of life. A subset of the cohort also includes children with a family history of autism (a diagnosed parent or sibling). Salivary testosterone levels were assessed at two time-points, just after the 2nd and 6th month of life. Autistic traits were measured using the Quantitative Checklist of Autism in Toddlers (Q-CHAT) when the children were 18 months of age.

Results

Salivary testosterone levels were significantly higher during 'mini-puberty' in the 2nd and 3rd month of life, compared to after the 6th month of life, in both males and females. There was no significant sex difference at either time-point. Log-transformed testosterone levels were not associated with autistic traits (Q-CHAT). There was no interaction effect with infant sex, autism family history or baseline testosterone levels after mini-puberty (at >6 months of age).

Conclusion

Both male and female infants have elevated levels of salivary testosterone during mini-puberty but in this relatively small sample this was not associated with their later autistic traits at 18 months or their family history of autism. This suggests that prenatal rather than postnatal testosterone levels are more relevant for understanding the causes of autism. Future studies should test these relationships in larger samples.

Androgens and child behavior: Color and toy preferences in children with congenital adrenal hyperplasia (CAH)

Human males and females show average gender/sex differences for certain psychological phenomena. Multiple factors may contribute to these differences, including sex chromosomes, exposure to gonadal hormones, and socialization or learning. This study investigated potential hormonal and socialization/learning influences on gender/sex differences in childhood preferences for color, specifically pink and red vs. blues, and for toys. Children (aged 4 to 11 years) with congenital adrenal hyperplasia (CAH, n = 43 girls and 37 boys), marked by elevated prenatal adrenal androgen exposure, and without CAH (n = 41 girls and 31 boys) were studied. Prior research indicates girls with CAH are masculinized for certain behaviors, such as toy choices, while boys with CAH generally do not differ from boys without CAH. In the current study, children indicated preferences for stereotyped hues of pink vs. blue as well as two control color pairs. They also indicated their preference between gender/sex-typed toys (doll vs. car) presented in black and white, in gender/sex-congruent colors (pink doll vs. blue car) and in gender/sex-incongruent colors (pink car vs. blue doll). Color findings: Control girls preferred stereotyped pink over blue more than boys or girls with CAH did; the latter two groups did not differ in their color preferences. No preference differences occurred for other color pairs. Toy findings: In black/white or gender/sex-congruent colors, boys preferred the car more than control girls or girls with CAH did, while girls with CAH preferred the car more than control girls did. In gender/sex-incongruent colors (pink car vs. blue doll), boys still preferred the car, while girls with CAH showed reduced and control girls showed increased preferences for the pink car compared to the car preferences in black/white. Results support learning theories of color preferences, perhaps also influenced by pre-existing toy preferences which may occur for other reasons, including early androgen exposure. Specifically, girls with CAH may have learned they do not enjoy stereotypical toys for girls, often colored pink, and pink coloring may subsequently diminish their preference for a car. Our results highlight the importance of gonadal hormones and learning in the development of childhood toy and color preferences.

Sex Differences in Neurodevelopmental Disorders: A Key Role for the Immune System

Sex differences are prominent defining features of neurodevelopmental disorders. Understanding the sex biases in these disorders can shed light on mechanisms leading to relative risk and resilience for the disorders, as well as more broadly advance our understanding of how sex differences may relate to brain development. The prevalence of neurodevelopmental disorders is increasing, and the two most common neurodevelopmental disorders, Autism Spectrum Disorder (ASD) and Attention-Deficit/Hyperactivity Disorder (ADHD) exhibit male-biases in prevalence rates and sex differences in symptomology. While the causes of neurodevelopmental disorders and their sex differences remain to be fully understood, increasing evidence suggests that the immune system plays a critical role in shaping development. In this chapter we discuss sex differences in prevalence and symptomology of ASD and ADHD, review sexual differentiation and immune regulation of neurodevelopment, and discuss findings from human and rodent studies of immune dysregulation and perinatal immune perturbation as they relate to potential mechanisms underlying neurodevelopmental disorders. This chapter will give an overview of how understanding sex differences in neuroimmune function in the context of neurodevelopmental disorders could lend insight into their etiologies and better treatment strategies.

Maternal androgens and autism spectrum disorder in the MARBLES prospective cohort study

Background

Maternal hormonal risk factors for autism spectrum disorder (ASD) in offspring could intersect genetic and environmental risk factors.

Objectives

This analysis explored ASD risk in association with maternal testosterone, androstenedione, and dehydroepiandrosterone (DHEA) measured in first, second, and third trimesters of pregnancy.

Methods

MARBLES is a prospective pregnancy cohort study based at the MIND Institute in Northern California that enrolls mothers who have at least one child previously diagnosed with ASD and are expecting, or planning to have another child. At 36 months the younger sibling is clinically classified as having ASD, or as non-typically developing (Non-TD), or typically developing (TD). Maternal androgens during pregnancy were measured in serum samples from 196 mothers. Multivariable logistic regression models estimated risk of ASD and Non-TD in offspring compared to TD, in relation to the log-transformed maternal androgen concentrations, at each trimester.

Results

Non-significant associations were observed, and borderline significant associations were only observed in some stratified unadjusted models. Second trimester maternal testosterone was non-significantly associated with ASD in female offspring, although not after adjustment, aRR 1.54 (95% CI 0.71, 3.33), and second trimester maternal DHEA was non-significantly associated with non-TD in male offspring, again not after adjustment, aRR 0.50 (95% CI 0.21, 1.21). Secondary analysis suggested that third trimester androgen concentrations in mothers with male offspring had significant or near significant associations with their child's Social Responsiveness Scale score.

Conclusion

No significant associations were found between maternal androgen concentrations and risk of ASD or Non-TD in the child.

Theories on the Link Between Autism Spectrum Conditions and Trans Gender Modality: a Systematic Review

While research on the prevalence of co-occurring autism spectrum conditions (ASC) and trans gender modality (TGM) is available, less is known about the underlying mechanism of this association. Insight is needed to improve treatment of trans autistic people. This review provides an overview of theories on the ASC-TGM link and the available evidence for/against them published between January 2016 and October 2020. A systematic search was performed in PubMed, PsycINFO, Web of Science, and Scopus. This resulted in 36 studies, in which 15 theories were identified. Results indicate all theories lack substantial empirical support. Unlikely and promising theories were identified. The most promising theories were those on resistance to social norms and weakened sex differences. Future directions are provided.

Autistic Traits, Empathizing-Systemizing, and Gender Diversity

Previous research indicates a link between autism and transgender and gender-diverse identities, though the association is not yet fully understood. The current study examined autistic traits (Autism Spectrum Quotient [AQ]), empathizing (Empathizing Quotient-Short [EQ-S]), and systemizing (Systemizing Quotient-Short [SQ-S]) in a sample of 89 adults and aimed to test whether gender-diverse individuals exhibit cognitive profiles consistent with predictions derived from the Extreme Male Brain (EMB) theory. As most research has considered only cisgender people, we recruited a more diverse sample by contacting > 200 UK LGBTQ+ organizations and posting on social media. A range of non-cisgender identities (e.g., transgender male, transgender female, non-binary, genderqueer, transmasculine) and non-heterosexual orientations (e.g., bisexual) were represented, and participants were categorized into one of four groups: (1) assigned female at birth but does not identify as female (transgender AFAB) (n = 32), (2) cisgender female (n = 21), (3) assigned male at birth but does not identify as male (transgender AMAB) (n = 18), and (4) cisgender male (n = 18). After controlling for age and autism diagnostic status, transgender AFAB participants had marginally higher AQ scores, and significantly higher SQ-S and systemizing-relative-to-empathizing (D) scores, compared with the cisgender female group. No such differences were detected between the transgender AMAB and cisgender male groups. Our findings are broadly in line with predictions derived from the EMB theory, though as no transgender AFAB participants reported being heterosexual, it was not possible to determine whether these effects relate specifically to gender identity, to sexual orientation, or to both.

Elevated prenatal maternal sex hormones, but not placental aromatase, are associated with child neurodevelopment

Fetal exposure to testosterone may contribute to vulnerability for autism spectrum disorder (ASD). It is hypothesized that placental aromatase prevents fetal exposure to maternal testosterone, however, this pathway and the implications for child neurodevelopment have not been fully explored. We examined the relationships between prenatal maternal testosterone and estradiol at 19.2 ± 1.3 weeks, cord blood testosterone and estradiol at birth, placental aromatase mRNA expression, and neurodevelopment using the Social Communication Questionnaire (SCQ), the Behavioral Assessment System for Children, 3rd Edition (BASC-3), and the Empathizing Quotient for Children (EQ-C) at 4.5-6.5 years of age in a sample of 270 Nulliparous-Mothers-to-be (nuMoM2b) study participants. Maternal testosterone levels were positively associated with SCQ scores, but the association was not significant after adjusting for maternal age at delivery, nor was there a significant interaction with sex. Maternal estradiol levels were negatively associated with BASC-3 Clinical Probability scores among males (n = 139). We report a significant interaction effect of cord blood testosterone and fetal sex on both total SCQ scores and t-scores on the Developmental Social Disorders subscale. Placental aromatase was not associated with any neurodevelopmental or hormone measure, but under conditions of low placental aromatase expression, high maternal testosterone was positively associated with SCQ scores in males (n = 46). No other associations between hormone levels and neurodevelopment were significant. Our findings provide a foundation for further investigation of the mechanisms through which maternal sex hormones and placental steroidogenesis may affect fetal hormone production and neurobehavior.

An investigation of a novel broad autism phenotype: increased facial masculinity among parents of children on the autism spectrum

The broad autism phenotype commonly refers to sub-clinical levels of autistic-like behaviour and cognition presented in biological relatives of autistic people. In a recent study, we reported findings suggesting that the broad autism phenotype may also be expressed in facial morphology, specifically increased facial masculinity. Increased facial masculinity has been reported among autistic children, as well as their non-autistic siblings. The present study builds on our previous findings by investigating the presence of increased facial masculinity among non-autistic parents of autistic children. Using a previously established method, a 'facial masculinity score' and several facial distances were calculated for each three-dimensional facial image of 192 parents of autistic children (58 males, 134 females) and 163 age-matched parents of non-autistic children (50 males, 113 females). While controlling for facial area and age, significantly higher masculinity scores and larger (more masculine) facial distances were observed in parents of autistic children relative to the comparison group, with effect sizes ranging from small to medium (0.16 ≤ d ≤ .41), regardless of sex. These findings add to an accumulating evidence base that the broad autism phenotype is expressed in physical characteristics and suggest that both maternal and paternal pathways are implicated in masculinized facial morphology.

No effects of siblings and twin testosterone transfer on autistic traits

Background

Having twin and non-twin siblings might influence autistic traits both prenatally and postnatally. The twin testosterone transfer hypothesis suggests that girls with a twin brother are exposed to higher levels of prenatal testosterone than girls with a twin sister, and that increased testosterone exposure masculinizes neural development and increases autistic traits. Postnatally, siblings may provide example behaviour, which could reduce autistic traits.

Methods

We studied pre- and postnatal influences of twin and non-twin siblings on mother and teacher-reported autistic traits in 7714 dizygotic twins. We examined the effect of sex of the proband child and of the siblings. We fitted regression models (for boys and girls separately) with sex of co-twin and having older and/or younger siblings of each sex as predictors.

Results

Girls' mother-reported autistic traits were slightly lower for those with a twin brother than those with a twin sister (β = -.08, p = .001, Cohen's d = -.13). This difference was not replicated in teacher-reported autistic traits (β = .01, p = .734). Boys' (mother and teacher-reported) autistic traits were not related to the sex of their co-twin (ps > 0.50). Teacher-reported autistic traits were slightly higher if girls had an older brother (β = .07, p = .013, Cohen's d = .12). Other than this small effect, we found no effect of non-twin siblings on autistic traits in either girls or boys (ps > .18).

Conclusions

We did not find increased autistic traits in girls with a twin brother compared to girls with a twin sister. This finding contributes to a body of literature that rejects the twin testosterone transfer hypothesis. In addition, we found little evidence for pre- and postnatal sibling influences. Our findings align with high heritability and absence of shared-environmental influences in ASD.

Is there an association between prenatal testosterone and autistic traits in adolescents?

Prenatal testosterone (pT) is a crucial component in physiological masculinization in humans. In line with the Prenatal Sex Steroid Theory of autism, some studies have found a positive correlation between pT and autistic traits in childhood. However, effects in adolescence have not been explored. Hormonal and environmental changes occurring during puberty may alter the strength or the nature of prenatal effects on autistic traits. The current study examines if pT relates to autistic traits in a non-clinical sample of adolescents and young adults (N = 97, 170 observations; age 13-21 years old). It also explores pT interactions with pubertal stage and timing. PT concentrations were measured from amniotic fluid extracted in the 2nd trimester of gestation via amniocentesis conducted for clinical purposes. Autistic traits were measured by self- and parent-reports on the Autism Spectrum Quotient (AQ) which provides a total score and 5 sub-scores (social skills, communication, imagination, attention switching and attention to detail). Self-reported pubertal stage was regressed on age to provide a measure of relative timing. We found no statistical evidence for a direct association between pT and autistic traits in this adolescent sample (males, females or full sample). Exploratory analyses suggested that pT correlated positively with autistic traits in adolescents with earlier puberty-onset, but statistical robustness of this finding was limited. Further exploratory post-hoc tests suggested the pT-by-pubertal timing interaction was stronger in males relative to females, in self-reported compared to parent-reported AQ and specifically for social traits. These findings require replication in larger samples. Findings have implications for understanding the effects of pT on human behavior, specifically existence of effects in adolescence.

Prenatal testosterone and sexually differentiated childhood play preferences: a meta-analysis of amniotic fluid studies

Sexually differentiated behaviour appears to emerge from a complex interaction of biological and socio-cultural factors, with prenatal exposure to steroid hormones such as testosterone thought to play a key role. Due to large sex differences being present from a very early age, much research has focussed on the influence these hormones may have on play preferences during childhood. We present an overview of the literature and a random-effects meta-analysis linking amniotic testosterone with sexually differentiated play preferences (k = 9, n = 493). The overall effect size estimate was in the theory-consistent direction (i.e., with higher levels of testosterone associated with more male-typical play preferences), though not statistically significant (r = 0.082, p = 0.274). However, after three hypothesised missing studies were imputed via the trim and fill procedure, a significant correlation emerged (r = 0.166, p = 0.014). Nevertheless, one sample was observed to exert a particularly large influence on the outcome of the analysis. Notably this was the second biggest sample and related to the largest effect size estimate. Though far from conclusive, the overall findings are consistent with the idea that individual differences in prenatal testosterone within the typical range predict sexually differentiated play preferences in early life. However, these effects may be small in magnitude and appear to vary considerably across studies.

Autism-Like Behavior in the Offspring of CYP11A1-Overexpressing Pregnant Rats

Autism spectrum disorders (ASD) represent a complex group of neurodevelopmental disorders that are characterized by impaired social behavior and communication as well as repetitive behavior and restricted interests. Prenatal exposure to high levels of testosterone and preeclampsia are thought to be risk factors of ASD. We had previously reported that overexpression of the mitochondrial cholesterol side-chain cleavage enzyme (CYP11A1) could lead to both preeclampsia-like symptoms and increased testosterone levels in pregnant rats. In this study, we investigated the association between high CYP11A1 levels in pregnant rats and autism-like behavior in their offspring. Timed-pregnant Sprague-Dawley (SD) rats were injected with CYP11A1 gene-carrying adenoviruses on gestational day 8.5, and their offspring were then compared with those from timed-pregnant control SD rats. Compared with their control counterparts, the offspring of the CYP11A1-ovexpressing dams displayed more symptoms of anxiety and spent less time in social interactions and more time in self-grooming and rearing, all indicators of autism-like behavior. Sequencing of the transcriptome in primary microglia from the offspring of CYP11A1-overexpressing dams revealed that immune pathways were highly activated, and the gamma-aminobutyric acid type A (GABAA) receptor genes were among the top differentially expressed genes. Using primary microglia cultures generated from neonatal rats, tumor necrosis factor-alpha expression was found to be elevated in the cells transfected with CYP11A1-carrying adenoviruses. Additionally, the offspring of CYP11A1-overexpressing dams displayed dysregulated GABAA receptor expression. Taken together, these results suggest that abnormal CYP11A1 gene expression in pregnant rats could lead to microglial immune activation and dysregulated GABAA receptor expression in their offspring and thereby anxiety and autism-related behavior. Our study suggests that the pathways regulated by CYP11A1 could be promising preventative and therapeutic targets for ASD.

Patterns of brain asymmetry associated with polygenic risks for autism and schizophrenia implicate language and executive functions but not brain masculinization

Autism spectrum disorder (ASD) and schizophrenia have been conceived as partly opposing disorders in terms of systemizing vs. empathizing cognitive styles, with resemblances to male vs. female average sex differences. Left-right asymmetry of the brain is an important aspect of its organization that shows average differences between the sexes and can be altered in both ASD and schizophrenia. Here we mapped multivariate associations of polygenic risk scores for ASD and schizophrenia with asymmetries of regional cerebral cortical surface area, thickness, and subcortical volume measures in 32,256 participants from the UK Biobank. Polygenic risks for the two disorders were positively correlated (r = 0.08, p = 7.13 × 10-50) and both were higher in females compared to males, consistent with biased participation against higher-risk males. Each polygenic risk score was associated with multivariate brain asymmetry after adjusting for sex, ASD r = 0.03, p = 2.17 × 10-9, and schizophrenia r = 0.04, p = 2.61 × 10-11, but the multivariate patterns were mostly distinct for the two polygenic risks and neither resembled average sex differences. Annotation based on meta-analyzed functional imaging data showed that both polygenic risks were associated with asymmetries of regions important for language and executive functions, consistent with behavioral associations that arose in phenome-wide association analysis. Overall, the results indicate that distinct patterns of subtly altered brain asymmetry may be functionally relevant manifestations of polygenic risks for ASD and schizophrenia, but do not support brain masculinization or feminization in their etiologies.

Brief Report: Facial Asymmetry and Autistic-Like Traits in the General Population

Atypical facial morphology, particularly increased facial asymmetry, has been identified in some individuals with Autism Spectrum Conditions (ASC). Many cognitive, behavioural and biological features associated with ASC also occur on a continuum in the general population. The aim of the present study was to examine subthreshold levels of autistic traits and facial morphology in non-autistic individuals. Facial asymmetry was measured using three-dimensional facial photogrammetry, and the Autism-spectrum Quotient was used to measure autistic-like traits in a community-ascertained sample of young adults (n = 289). After accounting for covariates, there were no significant associations observed between autistic-like traits and facial asymmetry, suggesting that any potential facial morphology differences linked to ASC may be limited to the clinical condition.

No relationship between prenatal or early postnatal androgen exposure and autistic traits: evidence using anogenital distance and penile length measurements at birth and 3 months of age

BACKGROUND

Autism is more prevalent in males than in females. Hypotheses related to the extreme male brain theory of autism suggest that heightened androgen exposure during early development contributes to autistic traits. Whilst prior research focused mostly on the prenatal period, the current study tests the influences of androgen exposure during both the prenatal and the early postnatal periods on autistic traits during childhood.

METHODS

Anthropometric measures that are putative biomarkers of early androgen exposure were employed. Anogenital distance (AGD) was measured at birth and 3 months of age in boys and girls. Penile length at birth and 3 months of age was also measured in boys. When the children were 9-13 years old, a parent-reported questionnaire (the 10-item children's version of the Autism Spectrum Quotient; AQ-10 Child) was used to assess autistic traits in 97 boys and 110 girls.

RESULTS

There were no significant associations between any of the AGD or penile length measures and scores on the AQ-10 Child in boys, girls or the entire sample.

CONCLUSIONS

The current study provides the first test of whether early measurements of AGD and/or penile length predict subsequent autistic traits. The current findings do not support a relationship between prenatal or early postnatal androgen exposure and autistic traits. The current study augments prior research showing no consistent relationship between early androgen exposure and autistic traits.

Medical symptoms and conditions in autistic women

The sex bias in autism diagnosis suggests the involvement of sex-specific endocrine mechanisms during prenatal development, but these hormones affect health throughout life. Therefore, the current study examined the association of autism and autistic traits with conditions and symptoms related to the sex-steroid system in adult women. In total, 1230 women (361 autistic), aged 15–77 years, reported on autistic traits and medical history. Medical diagnoses and symptoms were grouped by unsupervised factor analysis, and associations with autism diagnosis and autistic traits were explored. Higher rates of reproductive system diagnoses (odds ratio = 1.035, p = 0.024), prediabetes symptoms (odds ratio = 1.319, p = 0.001), irregular puberty onset (odds ratio = 1.458, p = 0.009), and menstrual length (odds ratio = 1.368, p = 0.034) and lower rates of metabolic and vascular conditions (odds ratio = 0.654, p = 0.013) were associated with diagnosis. Reproductive system diagnoses (β = 0.114, p = 0.000), prediabetes symptoms (β = 0.188, p = 0.000), menstrual length (β = 0.071, p = 0.014), irregular puberty onset (β = 0.149, p = 0.000), excessive menstruation symptoms (β = 0.097, p = 0.003), and hyperandrogenism symptoms (β = 0.062, p = 0.040) were also associated with autistic traits. Many of the conditions and symptoms found to be associated with autism or autistic traits are also related to conditions of steroid hormones and, specifically, the sex-steroid system. The study suggests an important role for steroids in autistic women, beyond prenatal development. Clinical implications are discussed.

Genetic and morphological estimates of androgen exposure predict social deficits in multiple neurodevelopmental disorder cohorts

BACKGROUND

Neurodevelopmental disorders (NDDs) such as autism spectrum disorder (ASD) display a strong male bias. Androgen exposure is profoundly increased in typical male development, but it also varies within the sexes, and previous work has sought to connect morphological proxies of androgen exposure, including digit ratio and facial morphology, to neurodevelopmental outcomes. The results of these studies have been mixed, and the relationships between androgen exposure and behavior remain unclear.

METHODS

Here, we measured both digit ratio masculinity (DRM) and facial landmark masculinity (FLM) in the same neurodevelopmental cohort (N = 763) and compared these proxies of androgen exposure to clinical and parent-reported features as well as polygenic risk scores.

RESULTS

We found that FLM was significantly associated with NDD diagnosis (ASD, ADHD, ID; all [Formula: see text]), while DRM was not. When testing for association with parent-reported problems, we found that both FLM and DRM were positively associated with concerns about social behavior ([Formula: see text], [Formula: see text]; [Formula: see text], [Formula: see text], respectively). Furthermore, we found evidence via polygenic risk scores (PRS) that DRM indexes masculinity via testosterone levels ([Formula: see text], [Formula: see text]), while FLM indexes masculinity through a negative relationship with sex hormone binding globulin (SHBG) levels ([Formula: see text], [Formula: see text]). Finally, using the SPARK cohort (N = 9419) we replicated the observed relationship between polygenic estimates of testosterone, SHBG, and social functioning ([Formula: see text], [Formula: see text], and [Formula: see text], [Formula: see text] for testosterone and SHBG, respectively). Remarkably, when considered over the extremes of each variable, these quantitative sex effects on social functioning were comparable to the effect of binary sex itself (binary male: [Formula: see text]; testosterone: [Formula: see text] from 0.1%-ile to 99.9%-ile; SHBG: [Formula: see text] from 0.1%-ile to 99.9%-ile).

LIMITATIONS

In the devGenes and SPARK cohorts, our analyses rely on indirect, rather than direct measurement of androgens and related molecules.

CONCLUSIONS

These findings and their replication in the large SPARK cohort lend support to the hypothesis that increasing net androgen exposure diminishes capacity for social functioning in both males and females.

Sexual Knowledge, Desires, and Experience of Adolescents and Young Adults With an Autism Spectrum Disorder: An Exploratory Study

Although most persons with an Autism Spectrum Disorder (ASD) wish to have romantic and/or sexual relationships, little is known about self-report sexuality of adolescents/young adults with ASD. In this exploratory study, 172 male and female adolescents/young adults (68 with ASD and 104 without ASD) completed an online version of the Sexual Behavior Scale-Third edition. Although many more similarities than differences were observed between the groups for views and desires about romantic relationships (e.g., wishing to have a girlfriend/boyfriend), fewer participants with ASD (mostly boys) had experience with a variety of sexual/dyadic behaviors, and approximately half of girls with ASD reported negative sexual experiences. Significantly higher rates of participants with ASD felt their knowledge about sexuality was limited and found it difficult to understand sexual education compared with typically developing (TD) participants. Significantly lower rates of participants with ASD reported that they identify to their assigned gender compared with TD participants. Multiple regressions revealed that being older at first diagnosis and possessing better knowledge about sexuality were significant predictors of both positive and negative sexual experience. This study explores strengths and challenges related with the sexual health of adolescents/young adults with ASD and implications for clinical and educational practice are discussed.

Associations of Maternal Androgen-Related Conditions With Risk of Autism Spectrum Disorder in Progeny and Mediation by Cardiovascular, Metabolic, and Fertility Factors

Fetal exposure to elevated androgens is thought to contribute to autism spectrum disorder (ASD) risk. However, data rely heavily on in utero androgens measurements, which also reflect fetal secretions. Thus, in utero hyperandrogenemia might indicate adverse autism-related neurogenesis that has already occurred affecting fetal androgen homeostasis, rather than being a cause of the disorder. Associations between maternal androgen-related conditions and ASD could more directly implicate androgens' etiological role. We examined the association between maternal hyperandrogenemia-related conditions, focusing primarily on polycystic ovarian syndrome (PCOS), and progeny ASD, in an Israeli cohort of 437,222 children born in 1999-2013. Odds ratios and 95% confidence intervals were estimated using generalized estimating equations. Multiple mediation analyses using natural effect models were conducted to evaluate combined mediation of the PCOS effect by androgen-related cardiovascular, metabolic, and fertility factors. Results indicated that children of mothers with PCOS had higher ASD odds compared with children of mothers without PCOS (odds ratio = 1.42, 95% confidence interval: 1.24,1.64), and this effect was only partly mediated by the factors considered. Elevated odds were also observed for other hyperandrogenemia-related conditions. Findings provide support for direct involvement of maternal hyperandrogenemia in ASD etiology. Alternatively, findings might reflect shared genetic and/or environmental factors independently affecting maternal androgen homeostasis and fetal neurodevelopment.

Second-to-Fourth Digit Ratio (2D:4D) in Psychiatric Disorders: A Systematic Review of Case-control Studies

The second-to-fourth digit ratio (2D:4D) is an indirect, retrospective, non-invasive measure that correlates negatively with intrauterine exposure to testosterone. The present meta-analysis aimed to evaluate if 2D:4D differs between patients with psychiatric disorders and controls. In September 2019, we searched in Web of Knowledge, PsycINFO, Embase, and CINHAL, and retrieved 619 papers. We finally included 43 case-control studies which compared the 2D:4D ratio of patients with autism spectrum disorder (ASD) (n = 16), schizophrenia (n = 8), gender non-conformity (n = 7), addictions (n = 5), attention deficit-hyperactivity disorder (ADHD) (n = 4), mood disorders (n = 2), and intellectual disability (n = 1) to non-clinical controls. Meta-analyses showed that, overall, psychiatric patients had lower 2D:4D than healthy controls (n = 43, overall sample = 9,484, mean difference = -0.0056, 95% confidence interval from -0.0093 to -0.002, I2 = 74%), with more pronounced differences in the right hand, males, and children. Considering psychiatric disorders individually, significant differences were found in the ASD, ADHD, and addictions groups, in which 2D:4D was significantly lower than healthy controls. Conversely, the right hand of males with schizophrenia showed higher 2D:4D than healthy controls. No other significant differences were detected. Although our results need to be cautiously interpreted and find limited applications in clinical practice, they may suggest that 2D:4D is altered in some psychopathological conditions, underlining the role of prenatal exposure to sex steroids in the etiology of psychiatric disorders.

The Prenatal Hormone Milieu in Autism Spectrum Disorder

Though the etiology of autism spectrum disorder (ASD) remains largely unknown, recent findings suggest that hormone dysregulation within the prenatal environment, in conjunction with genetic factors, may alter fetal neurodevelopment. Early emphasis has been placed on the potential role of in utero exposure to androgens, particularly testosterone, to theorize ASD as the manifestation of an "extreme male brain." The relationship between autism risk and obstetric conditions associated with inflammation and steroid dysregulation merits a much broader understanding of the in utero steroid environment and its potential influence on fetal neuroendocrine development. The exploration of hormone dysregulation in the prenatal environment and ASD development builds upon prior research publishing associations with obstetric conditions and ASD risk. The insight gained may be applied to the development of chronic adult metabolic diseases that share prenatal risk factors with ASD. Future research directions will also be discussed.

Prenatal androgen exposure and children's gender-typed behavior and toy and playmate preferences

We report findings from two studies investigating possible relations of prenatal androgen exposure to a broad measure of children's gender-typed behavior, as well as specifically to children's toy and playmate preferences. Study 1 investigated these outcomes for 43 girls and 38 boys, aged 4 to 11 years, with congenital adrenal hyperplasia (CAH, a genetic condition causing increased adrenal androgen production beginning prenatally) compared to similarly-aged, unaffected relatives (41 girls, 31 boys). The predicted sex differences were found for all of the outcome measures. Furthermore, girls with CAH showed increased male-typical and decreased female-typical behavior and toy and playmate preferences compared to unaffected girls. Study 2 investigated the relationship of amniotic fluid testosterone to gender-typed behavior and toy and playmate preferences in typically developing children (48 girls, 44 boys) aged 3 to 5 years. Although the predicted sex differences were found for all of the outcome measures, amniotic fluid testosterone was not a significant correlate, in the predicted direction, of any outcome measure for either sex. The results of study 1 provide additional support for an influence of prenatal androgen exposure on children's gender-typed behavior, including toy and playmate preferences. The results of study 2 do not, but amniotic fluid testosterone may be an insufficiently sensitive measure of early androgen exposure. A more sensitive and reliable measure of prenatal androgen exposure may be needed to consistently detect relations to later gender typed behavior in non-clinical populations.

Meconium androgens are correlated with ASD-related phenotypic traits in early childhood in a familial enriched risk cohort

BACKGROUND

Prenatal exposure to increased androgens has been suggested as a risk factor for autism spectrum disorder (ASD). This hypothesis has been examined by measurement of steroids in amniotic fluid, cord blood, saliva, and blood with mixed results.

METHODS

To provide an orthogonal measure of fetal exposure, this study used meconium, the first stool of a newborn, to measure prenatal androgen exposure from infants in the Early Autism Risk Longitudinal Investigation (EARLI). EARLI is a familial-enriched risk cohort that enrolled pregnant mothers who already had a child with an ASD diagnosis. In the younger child, we investigated the association between meconium unconjugated (u) and total (t) concentrations of major androgens testosterone (T), dehydroepiandrosterone (DHEA), and androstenedione (A4), and ASD-related traits at 12 and 36 months of age. Traits were measured at 12 months with Autism Observation Scale for Infants (AOSI) and at 36 months with total score on the Social Responsiveness Scale (SRS). One hundred and seventy children had meconium and AOSI, 140 had meconium and SRS, and 137 had meconium and both AOSI and SRS.

RESULTS

Separate robust linear regressions between each of the log-transformed androgens and log-transformed SRS scores revealed three-way interaction between sex of the child, sex of the proband, and testosterone concentration. In the adjusted analyses, t-T, u-A4, and u-DHEA (P ≤ 0.01) were positively associated with AOSI scores, while u-T (P = 0.004) and u-DHEA (P = 0.007) were positively associated with SRS total score among females with female probands (n = 10). Additionally, higher concentrations of u-T (P = 0.01) and t-T (P = 0.01) predicted higher SRS total score in males with male probands (n = 63). Limitations Since we explored three-way interactions, this resulted in a limited sample size for some analyses. This study was from an enriched-risk cohort which may limit generalizability, and this study used ASD-assessment scales as outcomes instead of diagnostic categories. Additionally, the novel use of meconium in this study limits the ability to compare the results in this cohort to others due to the paucity of research on meconium.

CONCLUSIONS

This study supports the utility of meconium for studies of endogenous fetal metabolism and suggests the sex of older siblings with autism should be considered as a biological variable in relevant studies.

Human gender development

Human gender-related behavior/psychology is shaped by a developmental system that involves numerous influences interacting over time. Understanding of the full range of elements in the system and how they interact is currently incomplete. The available evidence suggests, however, that early exposure to testosterone, postnatal socialization, e.g., by parents and peers, and self-socialization related to cognitive understanding of gender are important elements. This article focuses on prenatal and early neonatal influences of testosterone on gender-related psychological/behavioral outcomes, and contextualizes these hormonal influences within an understanding of socialization influences. There is consistent evidence that early testosterone exposure influences childhood gender role behavior, including sex-typical toy play, as well as gender identity and sexual orientation. Evidence for similar hormonal influences on spatial ability and on traits related to autism, or autistic spectrum disorder, is inconsistent. Evidence from girls exposed to elevated testosterone prenatally suggests that they experience alterations in processes of external socialization, as well as self-socialization, and that these, along with early testosterone exposure, shape gender-related outcomes.

Autistic traits, systemising, empathising, and theory of mind in transgender and non-binary adults

BACKGROUND

Prior research examining autistic traits in gender minority adults has reported mixed findings. Most prior studies did not include non-binary individuals. Little is known about the mechanisms shaping autistic traits in gender minority adults. This study examined autistic traits, as well as constructs related to the extreme male brain theory of autism and the mindblindness theory, in transgender and non-binary adults.

METHODS

An online survey was conducted to assess autism-related traits in 323 gender minority adults, including 74 transgender men (individuals assigned female at birth and identify as a man), 95 transgender women (individuals assigned male at birth and identify as a woman), 104 non-binary AFAB (individuals assigned female at birth and identify as non-binary), and 50 non-binary AMAB (individuals assigned male at birth and identify as non-binary). Autistic traits, systemising, empathising, and Theory of Mind (ToM) were measured using the Autism Spectrum Quotient (AQ), the short forms of the Systemising Quotient (SQ-Short) and the Empathy Quotient (EQ-Short), the 10-item version of the Empathy Quotient (EQ-10) and the Reading the Mind in the Eyes Test (Eyes Test). Participants' scores on these measures were compared with previously published scores based on large-scale general population samples including thousands of participants.

RESULTS

On average, compared with control females in the general population samples, both transgender men and non-binary AFAB scored significantly higher on the AQ and the SQ-Short but scored significantly lower on the EQ-Short, the EQ-10, and the Eyes Test. No clear or consistent group differences emerged when transgender women and non-binary AMAB were compared with control males.

LIMITATIONS

The present study does not have a large sample of gender minority adults. It has been argued that the measures employed may not provide a precise assessment of the psychological constructs of interest. The present study has a "non-clinical" sample. However, not all gender minorities have access to or require clinical services, and so a "non-clinical" sample may be more representative of the gender minority community as a whole than samples recruited through clinics.

CONCLUSIONS

The current findings suggest a "masculinised" autism-related profile and reduced ToM in transgender men and in non-binary AFAB. These findings might be interpreted to support the extreme male brain theory of autism and the mindblindness theory. Further research is needed to corroborate these findings.

The effects of sex on prevalence and mechanisms underlying neurodevelopmental disorders

Neurodevelopmental disorders occur more frequently in boys than in girls and often differ in presentation between the sexes. The sex differences in prevalence and presentation of autism spectrum disorder, intellectual disability, communication disorders, specific learning disabilities, attention deficit/hyperactivity disorder, Tourette's syndrome, and epilepsy are discussed, as well as sex differences in the patterns of comorbidities between these disorders. Prominent theories have been proposed to explain sex biases. These include genetic factors, sex hormones, sociological factors, cognitive differences between the sexes, and environmental insult. Despite the large body of research reviewed in this chapter, many aspects of sex-related effects in neurodevelopmental disorders remain poorly understood.

Endocrine Insights into the Pathophysiology of Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a class of neurodevelopmental disorders that affects males more frequently than females. Numerous genetic and environmental risk factors have been suggested to contribute to the development of ASD. However, no one factor can adequately explain either the frequency of the disorder or the male bias in its prevalence. Gonadal, thyroid, and glucocorticoid hormones all contribute to normal development of the brain, hence perturbations in either their patterns of secretion or their actions may constitute risk factors for ASD. Environmental factors may contribute to ASD etiology by influencing the development of neuroendocrine and neuroimmune systems during early life. Emerging evidence suggests that the placenta may be particularly important as a mediator of the actions of environmental and endocrine risk factors on the developing brain, with the male being particularly sensitive to these effects. Understanding how various risk factors integrate to influence neural development may facilitate a clearer understanding of the etiology of ASD.

2D:4D Suggests a Role of Prenatal Testosterone in Gender Dysphoria

Gender dysphoria (GD) reflects distress caused by incongruence between one's experienced gender identity and one's natal (assigned) gender. Previous studies suggest that high levels of prenatal testosterone (T) in natal females and low levels in natal males might contribute to GD. Here, we investigated if the 2D:4D digit ratio, a biomarker of prenatal T effects, is related to GD. We first report results from a large Iranian sample, comparing 2D:4D in 104 transwomen and 89 transmen against controls of the same natal sex. We found significantly lower (less masculine) 2D:4D in transwomen compared to control men. We then conducted random-effects meta-analyses of relevant studies including our own (k = 6, N = 925 for transwomen and k = 6, N = 757 for transmen). In line with the hypothesized prenatal T effects, transwomen showed significantly feminized 2D:4D (d ≈ 0.24). Conversely, transmen showed masculinized 2D:4D (d ≈ - 0.28); however, large unaccounted heterogeneity across studies emerged, which makes this effect less meaningful. These findings support the idea that high levels of prenatal T in natal females and low levels in natal males play a part in the etiology of GD. As we discuss, this adds to the evidence demonstrating the convergent validity of 2D:4D as a marker of prenatal T effects.

A broad autism phenotype expressed in facial morphology

Autism spectrum disorder is a heritable neurodevelopmental condition diagnosed based on social and communication differences. There is strong evidence that cognitive and behavioural changes associated with clinical autism aggregate with biological relatives but in milder form, commonly referred to as the 'broad autism phenotype'. The present study builds on our previous findings of increased facial masculinity in autistic children (Sci. Rep., 7:9348, 2017) by examining whether facial masculinity represents as a broad autism phenotype in 55 non-autistic siblings (25 girls) of autistic children. Using 3D facial photogrammetry and age-matched control groups of children without a family history of ASD, we found that facial features of male siblings were more masculine than those of male controls (n = 69; p < 0.001, d = 0.81 [0.36, 1.26]). Facial features of female siblings were also more masculine than the features of female controls (n = 60; p = 0.005, d = 0.63 [0.16, 1.10]). Overall, we demonstrated for males and females that facial masculinity in non-autistic siblings is increased compared to same-sex comparison groups. These data provide the first evidence for a broad autism phenotype expressed in a physical characteristic, which has wider implications for our understanding of the interplay between physical and cognitive development in humans.

Foetal oestrogens and autism

Elevated latent prenatal steroidogenic activity has been found in the amniotic fluid of autistic boys, based on measuring prenatal androgens and other steroid hormones. To date, it is unclear if other prenatal steroids also contribute to autism likelihood. Prenatal oestrogens need to be investigated, as they play a key role in synaptogenesis and corticogenesis during prenatal development, in both males and females. Here we test whether levels of prenatal oestriol, oestradiol, oestrone and oestrone sulphate in amniotic fluid are associated with autism, in the same Danish Historic Birth Cohort, in which prenatal androgens were measured, using univariate logistic regression (n = 98 cases, n = 177 controls). We also make a like-to-like comparison between the prenatal oestrogens and androgens. Oestradiol, oestrone, oestriol and progesterone each related to autism in univariate analyses after correction with false discovery rate. A comparison of standardised odds ratios showed that oestradiol, oestrone and progesterone had the largest effects on autism likelihood. These results for the first time show that prenatal oestrogens contribute to autism likelihood, extending the finding of elevated prenatal steroidogenic activity in autism. This likely affects sexual differentiation, brain development and function.

Sex/gender differences in neurology and psychiatry: Autism

Autism is a heterogenous set of early-onset neurodevelopmental conditions that are more prevalent in males than in females. Due to the high phenotypic, neurobiological, developmental, and etiological heterogeneity in the autism spectrum, recent research programs are increasingly exploring whether sex- and gender-related factors could be helpful markers to clarify the heterogeneity in autism and work toward a personalized approach to intervention and support. In this chapter, we summarize recent clinical and neuroscientific research addressing sex/gender influences in autism and explore how sex/gender-based investigations shed light on similar or different underlying neurodevelopmental mechanisms of autism by sex/gender. We review evidence that may help to explain some of the underlying sex-related biological mechanisms associated with autism, including genetics and the effects of sex steroid hormones in the prenatal environment. We conclude that current research points toward coexisting quantitative and, perhaps more evidently, qualitative sex/gender-modulation effects in autism across multiple neurobiological aspects. However, converging findings of specific neurobiological presentations and sex/gender-informed mechanisms cutting across the many subgroups within the autism spectrum are still lacking. Future research should use big data approaches and new stratification methods to decompose sex/gender-related heterogeneity in autism and work toward personalized, sex/gender-informed intervention and support for autistic people.

Sex-specific variation in facial masculinity/femininity associated with autistic traits in the general population

Reports linking prenatal testosterone exposure to autistic traits and to a masculinized face structure have motivated research investigating whether autism is associated with facial masculinization. This association has been reported with greater consistency for females than for males, in studies comparing groups with high and low levels of autistic traits. In the present study, we conducted two experiments to examine facial masculinity/femininity in 151 neurotypical adults selected for either low, mid-range, or high levels of autistic traits. In the first experiment, their three-dimensional facial photographs were subjectively rated by 41 raters for masculinity/femininity and were objectively analysed. In the second experiment, we generated 6-face composite images, which were rated by another 36 raters. Across both experiments, findings were consistent for ratings of photographs and composite images. For females, a linear relationship was observed where femininity ratings decreased as a function of higher levels of autistic traits. For males, we found a U-shaped function where males with mid-range levels of traits were rated lowest on masculinity. Objective facial analyses revealed that higher levels of autistic traits were associated with less feminine facial structures in females and less masculine structures in males. These results suggest sex-specific relationships between autistic traits and facial masculinity/femininity.

Opposite-sex and same-sex twin studies of physiological, cognitive and behavioral traits

A scientific interest in opposite-sex (OS) twins comes from animal studies showing hormone transfer between fetuses in utero. A parallel effect in humans may occur, especially for OS females who may be exposed to androgens, in particular testosterone, from the male co-twin. Conversely, OS males may be exposed to lower levels of prenatal testosterone than do same-sex (SS) males. In this special issue, we reviewed published studies investigating potential differences between OS and SS twins in physiological, cognitive and behavioral traits focusing on the Twin Testosterone Transfer (TTT) hypothesis. Sixty articles fulfilled the eligibility criteria including 23 studies published since the review by Tapp et al. (2011). In general, studies of cognition are conflicting, but it is the phenotype for which most support for the TTT hypothesis is found. Less consistent evidence has been found regarding physiological and behavioral traits. We hope that this special issue will stimulate a discussion about how an investigation of the TTT hypothesis should continue in future research.

Hypogonadotrophic hypogonadism, delayed puberty and risk for neurodevelopmental disorders

Hypogonadotrophic hypogonadism (HH) is a rare disorder that manifests absent puberty and infertility. Genetic syndromes with hypogonadism, such as Klinefelter syndrome, are associated with an increased risk of neurodevelopmental disorders (NDDs). However, it is not clear whether patients with HH or transient delayed puberty in general, have an increased risk of NDDs. We performed a register-based study on a national cohort of 264 patients with HH and 7447 patients diagnosed with delayed puberty that was matched with 2640 and 74 470 controls, respectively. The outcome was defined as having any of the following NDD diagnoses: (i) autism spectrum disorder (ASD); (ii) attention deficit hyperactivity disorder (ADHD); or (iii) intellectual disability (ID). Additional sensitivity analyses were performed to control for different parental and birth variables, as well as diagnosed malformation syndromes and chromosomal anomalies (ie, Down's and Turner syndromes). Patients with HH had increased risk for being diagnosed with ASD (odds ratio [OR] = 5.7; 95% confidence interval [CI] = 2.6-12.6), ADHD (OR = 3.0; 95% CI = 1.8-5.1) and ID (OR = 18.0; 95% CI = 8.9-36.3) compared to controls. Patients with delayed puberty also had a significantly increased risk of being diagnosed with an NDD. These associations remained significant after adjustments. This is the first study to demonstrate a significant association between HH, delayed puberty and NDDs in a population-based cohort. Clinicians should be aware of the overlap between these disorders. Further studies should explore the mechanisms behind these associations.

Novel combined insulin-like 3 variations of a single nucleotide in cryptorchidism

Background Insulin-like 3 hormone (INSL3) is involved in the process of testicular descent, and has been thoroughly studied in cryptorchidism. However, INSL3 allelic variations found in the human genome were heterozygous and only a few of them were found exclusively in patients with cryptorchidism. Under this perspective, we aimed to study the presence of INSL3 allelic variations in a cohort of patients with cryptorchidism and to estimate their potential consequences. Methods Blood samples were collected from 46 male patients with non-syndromic cryptorchidism and from 43 age-matched controls. DNA extraction and polymerase chain reaction (PCR) were performed for exons 1 and 2 of the INSL3 gene in all subjects. Sequencing analysis was carried out on the PCR products. All data were grouped according to testicular location. Results Seven variations of a single nucleotide (SNVs) were identified both in patients with cryptorchidism and in controls: rs2286663 (c.27G > A), rs1047233 (c.126A > G) and rs6523 (c.178A > G) at exon 1, rs74531687 (c.191-30C > T) at the intron, rs121912556 (c.305G > A) at exon 2 and rs17750642 (c.*101C > A) and rs1003887 (c.*263G > A) at the untranslated region (UTR). The allelic variants rs74531687 and rs121912556 were found for the first time in the Greek population. The novel homozygotic combination of the three allelic variants rs1047233-rs6523-rs1003887 seemed to present a stronger correlation with more severe forms of cryptorchidism. Conclusions The combination of specific INSL3 SNVs rather than the existence of each one of them alone may offer a new insight into the involvement of allelic variants in phenotypic variability and severity.

Does testosterone impair men's cognitive empathy? Evidence from two large-scale randomized controlled trials

The capacity to infer others' mental states (known as 'mind reading' and 'cognitive empathy') is essential for social interactions across species, and its impairment characterizes psychopathological conditions such as autism spectrum disorder and schizophrenia. Previous studies reported that testosterone administration impaired cognitive empathy in healthy humans, and that a putative biomarker of prenatal testosterone exposure (finger digit ratios) moderated the effect. However, empirical support for the relationship has relied on small sample studies with mixed evidence. We investigate the reliability and generalizability of the relationship in two large-scale double-blind placebo-controlled experiments in young men (n = 243 and n = 400), using two different testosterone administration protocols. We find no evidence that cognitive empathy is impaired by testosterone administration or associated with digit ratios. With an unprecedented combined sample size, these results counter current theories and previous high-profile reports, and demonstrate that previous investigations of this topic have been statistically underpowered.

Mental Health of a Large Group of Adults With Disorders of Sex Development in Six European Countries

OBJECTIVE

The aim of the study was to evaluate psychiatric symptoms among 1022 persons with various disorders of sex development (DSDs).

METHODS

The study was a European multicenter cross-sectional clinical evaluation in six countries. The mean (SD) age of participants was 32.1 (13.4) years. The cohort consisted of 325 individuals with Turner syndrome, 219 individuals with Klinefelter syndrome (KS), female individuals with various XY-DSD conditions (107 with and 67 without androgenization), 87 male individuals with XY-DSD conditions, and 221 female individuals with congenital adrenal hyperplasia. The Hospital Anxiety and Depression Scale, the Short Autism Spectrum Quotient, the Adult Attention-Deficit/Hyperactivity Disorder Self-Report Scale, and self-reported mental health history were used to assess psychiatric symptoms.

RESULTS

Across the six DSD diagnostic groups, clinical cutoff symptom scores were reached in 19.5% of participants for anxiety, in 7.1% for depression, in 4.1% for attention-deficit/hyperactivity disorder, and in 9.1% for autism. The mean depression and anxiety scores were higher compared with population norms in men with KS and men with XY-DSD. Compared with participants with other DSD conditions, men with KS reported significantly more mental health symptoms. Self-esteem, satisfaction with care, body dissatisfaction, and experiences of shame were associated with psychiatric symptoms in many DSD conditions.

CONCLUSIONS

A substantial minority of adults with DSD, with KS in particular, experience psychiatric morbidity. Across DSD conditions, adults may share feelings of shame. Developing a positive self-esteem and body image may be challenging. Multidisciplinary DSD care that involves specialized mental health support can be of important value.

TRIAL REGISTRATION

German Clinical Trials Register DRKS00006072.

Prenatal testosterone exposure is associated with delay of gratification and attention problems/overactive behavior in 3-year-old boys

Sex differences in self-control become apparent during preschool years. Girls are better able to delay their gratification and show less attention problems and overactive behavior than boys. In this context, organizational effects of gonadal steroids affecting the neural circuitry underlying self-control could be responsible for these early sex differences. In the present study testosterone levels measured in amniotic fluid (via ultra performance liquid chromatography and tandem mass spectrometry) were used to examine the role of organizational sex hormones on self-control. One hundred and twenty-two 40-month-old children participated in a delay of gratification task (DoG task) and their parents reported on their attention problems and overactive behavior. Girls waited significantly longer for their preferred reward than boys, and significantly more girls than boys waited the maximum period of time, providing evidence for sex differences in delay of gratification. Boys that were rated as suffering from more attention problems and overactive behavior waited significantly shorter in the DoG task. Amniotic testosterone measures were reliable in boys only. Most importantly, boys who waited shorter in the DoG task and boys who were reported to suffer from more attention problems and overactive behavior had higher prenatal testosterone levels. These findings extend our knowledge concerning organizational effects of testosterone on the brain circuitry underlying self-control in boys, and are of relevance for understanding how sex differences in behavioral disorders are connected with a lack of self-control.

Children born to women with polycystic ovary syndrome-short- and long-term impacts on health and development

Maternal PCOS status may negatively influence offspring infant and childhood growth, cardiometabolic health, reproductive health, and neurodevelopment. Current findings across studies are divergent, often because of small numbers of subjects, as well as heterogeneous selection criteria, ethnicities, and definitions of control groups. Coexisting maternal obesity, pregnancy complications, and comorbidity make it difficult to identify the contribution of maternal PCOS. Large, prospective, international, multiethnic studies with standardized investigation protocols and questionnaires on PCOS offspring health and development are needed.

The Co-occurrence of Gender Dysphoria and Autism Spectrum Disorder in Adults: An Analysis of Cross-Sectional and Clinical Chart Data

Quantitative studies indicate an overrepresentation of ASD in individuals with GD. This study aims to determine the prevalence of autistic traits or ASD in adults with GD using two different data collection methods: (1) cross-sectional data using the social responsiveness scale-adults (SRS-A) and the autism quotient (AQ) (n = 63). (2) Clinical chart data (n = 532). Mean SRS-A scores were significantly higher compared to a norm population. Almost 5% of the patients with GD scored above the cut-off as measured by the AQ. In 32 patients (6%), a certain ASD diagnosis was found in the patient files, which is sixfold higher compared to the general population. Significantly more "birth assigned male" were affected compared to "birth assigned female".

Emotional and behavioral adjustment in 4 to 11-year-old boys and girls with classic congenital adrenal hyperplasia and unaffected siblings

It has been suggested that atypical hormone environments during early development may contribute to subsequent development of psychopathology. Also, it has been suggested that individuals with the autosomal recessive genetic variant, classic congenital adrenal hyperplasia (CAH), might be at increased risk of psychopathology. The present study examined emotional and behavioral adjustment in young children with CAH and their unaffected siblings in the United Kingdom. The parent-reported version of the Strengths and Difficulties Questionnaire (SDQ) was employed to assess adjustment in children aged 4 to 11 years. There were 38 boys with CAH, 43 girls with CAH, 23 unaffected brothers, and 31 unaffected sisters. No differences in emotional or behavioral problems were found between boys or girls with CAH and unaffected same-sex siblings. In addition, affected and unaffected boys in the current sample generally did not differ from boys in the general population. However, compared with girls in the general population, girls with CAH had more difficulties related to conduct problems, hyperactivity/ inattention, and prosocial behavior, and unaffected sisters had more difficulties related to peer problems, conduct problems, and prosocial behavior. These findings suggest that both girls with CAH and unaffected sisters of girls or boys with CAH may be at increased risk of developing behavioral problems. Potential influences related to the early hormone environment, familial process, and social stigma are considered.

No relationship between autistic traits and salivary testosterone concentrations in men from the general population

It is suggested that testosterone may play a part in the higher prevalence of Autism Spectrum Disorder (ASD) in males compared to females. Previous studies have reported elevated postnatal testosterone levels in children and women with ASD but not in men. We compared levels of salivary testosterone across 67 undergraduate males (M_age 19.5 yrs, SD 1.92) selected for low, mid-range and high levels of autistic traits assessed using the Autism-spectrum Quotient. Analyses revealed no significant differences in testosterone concentrations across the three groups. The current data add to the increasing evidence for the lack of relationship between autistic traits and postnatal levels of testosterone in men.

Risk of epilepsy in opposite-sex and same-sex twins: a twin cohort study

Background

There is a complex interaction between female and male sex hormones and the risk of epilepsy. Whether prenatal exposure to higher levels of sex hormones affects the development of epilepsy in childhood or later in life is not well known. The sex hormone environment of fetuses may be affected by the sex of the co-twin. We estimated the risk of epilepsy for twins with an opposite-sex (OS) co-twin compared with twins with a same-sex (SS) co-twin.

Methods

From the Danish Twin Registry, we identified OS female twins (n = 11,078), SS female twins (n = 19,186), OS male twins (n = 11,080), and SS male twins (n = 20,207) born between 1977 and 2009. The SS twins include monozygotic twins, dizygotic twins, and twins with unknown zygosity. These children were followed up from day 29 after birth until diagnosis of epilepsy, death, emigration, or end of follow-up (31 December 2011) whichever came first. Information on diagnosis of epilepsy was obtained from the Danish National Patient Registry. We calculated hazard ratios (HRs) and 95% confidence intervals (CIs) for epilepsy in the OS twins using a Cox proportional hazards regression model compared with the SS twins. To account for the correlation of twins from the same mother when estimating standard errors, we used the cluster option in Stata.

Results

We identified 152 OS female twins, 282 SS female twins, 162 OS male twins, and 335 SS male twins diagnosed with epilepsy corresponding to an incidence rate of 9.9 and 9.7 per 10,000 person years for the OS and SS female twins, and 10.6 and 10.9 per 10,000 person years for the OS and SS male twins, respectively. We found a similar risk of epilepsy among the OS and SS female twins [HR = 1.01; 95% CI 0.83–1.24] as well as among the OS and SS male twins [HR = 0.94; 95% CI 0.78–1.14]

Conclusions

In this population-based study of Danish twins, we did not find difference in the risk of epilepsy between twins with an OS co-twin and twins with a SS co-twin. This applied to both female and male twins. The study therefore does not support the hypothesis that subtle hormone difference in fetal life due to co-twin may play a role in the development of epilepsy later in life.