The effect of early life stress on the cognitive phenotype of children with an extra X chromosome (47,XXY/47,XXX)

Klinefelter Syndrome: A Genetic Disorder Leading to Neuroendocrine Modifications and Psychopathological Vulnerabilities in Children-A Literature Review and Case Report

Klinefelter syndrome (KS), characterized by an additional X-chromosome in males, manifests in a wide range of neuroendocrine and psychiatric symptoms. Individuals with KS often face increased risks of hormonal dysfunction, leading to depression and anxiety, although extended research during pediatric and adolescent age is still limited. This critical phase, decisive for KS children, is influenced by a combination of genetic, environmental and familial factors, which impact brain plasticity. In this report, we reviewed, in a narrative form, the crucial KS psychopathological hallmarks in children. To better describe neuroendocrine and neuropsychiatric outcomes in children with KS, we presented the case of an 11-year-old prepubertal child with mosaic KS who was referred to our Center of Developmental Psychopathology due to a decline in his academic performance, excessive daytime fatigue and increased distractibility over the past few months. Family history revealed psychiatric conditions among first- and second-degree relatives, including recently divorced parents and a 15-year-old sister. Early-onset persistent depressive disorder and anxious traits were diagnosed. Timely identification of susceptible children, with thorough examination of familial psychiatric history, environmental influences and neurocognitive profile, alongside targeted interventions, could potentially mitigate lifelong psychopathology-related disabilities in pediatric and adolescent KS cases, including those with mosaic KS.

Resting-state functional connectivity in adults with 47,XXX: a 7 Tesla MRI study

Triple X syndrome is a sex chromosomal aneuploidy characterized by the presence of a supernumerary X chromosome, resulting in a karyotype of 47,XXX in affected females. It has been associated with a variable cognitive, behavioral, and psychiatric phenotype, but little is known about its effects on brain function. We therefore conducted 7 T resting-state functional magnetic resonance imaging and compared data of 19 adult individuals with 47,XXX and 21 age-matched healthy control women using independent component analysis and dual regression. Additionally, we examined potential relationships between social cognition and social functioning scores, and IQ, and mean functional connectivity values. The 47,XXX group showed significantly increased functional connectivity of the fronto-parietal resting-state network with the right postcentral gyrus. Resting-state functional connectivity (rsFC) variability was not associated with IQ and social cognition and social functioning deficits in the participants with 47,XXX. We thus observed an effect of a supernumerary X chromosome in adult women on fronto-parietal rsFC. These findings provide additional insight into the role of the X chromosome on functional connectivity of the brain. Further research is needed to understand the clinical implications of altered rsFC in 47,XXX.

Supporting students with sex chromosome aneuploidies in educational settings: Results of a nationwide survey

Children with sex chromosome aneuploidies (SCAs) are at an increased risk for neurocognitive and behavioral disorders that may interfere with academic success, including early developmental delays, learning disabilities, executive function problems, and social communication deficits. The present national survey aimed to update and extend our understanding of school supports and educational outcomes for students with these increasingly common genetic diagnoses. Parents of children with a diagnosed SCA, birth to 21 years, living in the United States (N = 248), responded to an electronic survey with questions focused on school support plans, academic accommodations, educational therapies, school completion, and perceptions of educator awareness of SCAs. Results revealed high rates of delayed kindergarten, grade retention in primary years, and educational support plans (IEPs = 71%; Section 504 Plans = 26%). A majority (73%) of respondents with children over age 18 years (N = 41) reported their children successfully completed high school, and nearly half (46%) pursued post-secondary education opportunities. Many parents reported their children's educators had little to no knowledge of SCA conditions, justifying a need to train teachers and policy makers in the unique educational needs of children and adolescents with SCAs. School psychologists should be aware of the frequent need for accommodations and individualized support plans in this population so they can support children and families by advocating for early and comprehensive evaluations and intervention plans.

Altered subcortical and cortical brain morphology in adult women with 47,XXX: a 7-Tesla magnetic resonance imaging study

Background

Triple X syndrome (47,XXX) is a relatively common sex chromosomal aneuploidy characterized by the presence of a supernumerary X chromosome in females and has been associated with a variable cognitive, behavioural and psychiatric phenotype. 47,XXX may serve as a suitable model for studying the effect of genetic architecture on brain morphology. Previous studies have shown alterations in brain structure in 47,XXX particularly in childhood and adolescence. In this study, we examined subcortical and cortical brain morphology in adult women with 47,XXX using ultra-high field 7T MRI. Given previous evidence of impaired social functioning and emotion recognition in adults with 47,XXX, we also investigated the relationship of these functions with brain morphology.

Methods

Twenty-one adult women with 47,XXX and 22 age- and sex-matched healthy controls were included. Structural T1-weighted images were acquired using a 7-Tesla magnetic resonance scanner. Measures of subcortical brain volumes, cortical surface area and thickness, and cortical folding were obtained and compared between the groups using general linear models. Additionally, we examined potential relationships between brain outcome measures and social functioning and social cognition in 47,XXX using correlation analyses.

Results

Adults with 47,XXX showed lower volumes of the thalamus, caudate, putamen, hippocampus, nucleus accumbens and pallidum, and larger lateral ventricle volumes. Lower surface area was found in the superior frontal gyrus and superior temporal gyrus in 47,XXX participants compared to healthy controls. Altered cortical thickness and cortical folding were not present in 47,XXX. Cortical thickness was associated with social cognition in 47,XXX.

Conclusions

Results suggest that a supernumerary X chromosome in females affects subcortical and lateral ventricle volumes, and cortical surface area in adulthood. 47,XXX may serve as a suitable model for studying genetic influences on structural brain morphology across developmental stages in order to understand neurobiological mechanisms underlying cognitive and behavioural impairments.

Supplementary Information

The online version contains supplementary material available at 10.1186/s11689-022-09425-1.

European academy of andrology guidelines on Klinefelter Syndrome Endorsing Organization: European Society of Endocrinology

BACKGROUND

Knowledge about Klinefelter syndrome (KS) has increased substantially since its first description almost 80 years ago. A variety of treatment options concerning the spectrum of symptoms associated with KS exists, also regarding aspects beyond testicular dysfunction. Nevertheless, the diagnostic rate is still low in relation to prevalence and no international guidelines are available for KS.

OBJECTIVE

To create the first European Academy of Andrology (EAA) guidelines on KS.

METHODS

An expert group of academicians appointed by the EAA generated a consensus guideline according to the GRADE (Grading of Recommendations, Assessment, Development and Evaluation) system.

RESULTS

Clinical features are highly variable among patients with KS, although common characteristics are severely attenuated spermatogenesis and Leydig cell impairment, resulting in azoospermia and hypergonadotropic hypogonadism. In addition, various manifestations of neurocognitive and psychosocial phenotypes have been described as well as an increased prevalence of adverse cardiovascular, metabolic and bone-related conditions which might explain the increased morbidity/mortality in KS. Moreover, compared to the general male population, a higher prevalence of dental, coagulation and autoimmune disorders is likely to exist in patients with KS. Both genetic and epigenetic effects due to the supernumerary X chromosome as well as testosterone deficiency contribute to this pathological pattern. The majority of patients with KS is diagnosed during adulthood, but symptoms can already become obvious during infancy, childhood or adolescence. The paediatric and juvenile patients with KS require specific attention regarding their development and fertility.

CONCLUSION

These guidelines provide recommendations and suggestions to care for patients with KS in various developmental stages ranging from childhood and adolescence to adulthood. This advice is based on recent research data and respective evaluations as well as validations performed by a group of experts.

Adaptive functioning in children and adolescents with Trisomy X: An exploratory analysis

Identifying the factors related to adaptive functioning will improve the information available to families and providers of females with Trisomy X. Cognitive and behavioral features were assessed in 50 females ages 12.2 ± 3.6 years using the Behavior Assessment System for Children Second Edition (BASC-2) and Wechsler Scales of Intelligence. Executive functioning, social skills, and autistic traits were evaluated in a subset. Adaptive functioning was assessed using the BASC-2 adaptive skills composite score (ASC). Participants were classified as average adaptive skills (ASC T-score > 40) or deficits (ASC T-score < 40). Group comparisons were conducted. Multiple linear regression examined which factors contributed to ASC score. Twenty-eight females (55.6%) had adaptive skills deficits with functional communication being the most commonly affected adaptive domain. The group with ASC in the average range had higher verbal IQ (VIQ) and lower rates of numerous behavioral concerns. Internalizing behavior composite, DSM-IV inattentive symptoms score, and VIQ were significant predictors of ASC. Prenatally diagnosed females comprised over 70% of those with average adaptive skills. In this study, internalizing behaviors, inattentive ADHD symptoms, and VIQ were associated with poorer adaptive functioning. Early interventions targeting internalizing behaviors, attention/executive functioning, and communication skills may improve adaptive skills and deserve further study.

Early neurodevelopmental and medical profile in children with sex chromosome trisomies: Background for the prospective eXtraordinarY babies study to identify early risk factors and targets for intervention

Sex chromosome trisomies (SCT), including Klinefelter syndrome/XXY, Trisomy X, and XYY syndrome, occur in 1 of every 500 births. The past decades of research have resulted in a broadening of known associated medical comorbidities as well as advances in psychological research. This review summarizes what is known about early neurodevelopmental, behavioral, and medical manifestations in young children with SCT. We focus on recent research and unanswered questions related to the risk for neurodevelopmental disorders that commonly present in the first years of life and discuss the medical and endocrine manifestations of SCT at this young age. The increasing rate of prenatal SCT diagnoses provides the opportunity to address gaps in the existing literature in a new birth cohort, leading to development of the eXtraordinarY Babies Study. This study aims to better describe and compare the natural history of SCT conditions, identify predictors of positive and negative outcomes in SCT, evaluate developmental and autism screening measures commonly used in primary care practices for the SCT population, and build a rich data set linked to a bank of biological samples for future study. Results from this study and ongoing international research efforts will inform evidence-based care and improve health and neurodevelopmental outcomes.

A review of neurocognitive functioning and risk for psychopathology in sex chromosome trisomy (47,XXY, 47,XXX, 47, XYY)

PURPOSE OF REVIEW

About one in 650-1000 children is born with an extra X or Y chromosome, referred to as sex chromosome trisomies (SCTs). Studying SCTs may uncover unique insights in neurodevelopmental pathways underlying the risk for neurobehavioral problems and psychopathology. There is also a clinical need for more knowledge about the phenotype of SCT with the recent introduction of noninvasive prenatal screening.

RECENT FINDINGS

The reviewed studies illustrate an increased vulnerability for psychopathology such as (symptoms of) autism spectrum disorder, attention-deficit/hyperactivity disorder, anxiety, depression and, to a lesser degree, psychotic disorders. Although traditionally the primary focus has been on language and learning problems, recent research suggests that impairments in executive functioning, social cognition and emotion regulation may also be key factors underlying the risk for neurobehavioral problems.

SUMMARY

The research field of SCT is in need of a more longitudinal perspective to identify early markers of 'at risk' development, and to assess the effectiveness of early interventions. Neurocognitive markers that signal compromised neurodevelopment may prove to be helpful in this. Variability in the SCT phenotype provides a unique opportunity to identify not only genetic but also environmental factors that shape neurodevelopmental outcome, calling for studies focused on understanding individual differences.

Language phenotypes in children with sex chromosome trisomies

Background Sex chromosome trisomies (47,XXX, 47,XXY and 47,XYY) are known to be a risk factor for language disorder, but it is hard to predict outcomes, because many cases are identified only when problems are found. Methods We recruited children aged 5-16 years with all three types of trisomy, and divided them into a High Bias group, identified in the course of investigations for neurodevelopmental problems, and a Low Bias group, identified via prenatal screening or other medical investigations. Children from a twin sample were used to compare pattern and severity of language problems: they were subdivided according to parental concerns about language/history of speech-language therapy into a No Concerns group (N = 118) and a Language Concerns group (N = 57). Children were assessed on a psychometric battery and a standardized parent checklist. After excluding children with intellectual disability, autism or hearing problems, the sample included 28 XXX, 18 XXY and 14 XYY Low Bias cases and 7 XXX, 13 XXY and 17 XYY High Bias cases. Results Variation within each trisomy group was substantial: within the Low Bias group, overall language scores were depressed relative to normative data, but around one third had no evidence of problems. There was no effect of trisomy type, and the test profile was similar to the Language Concerns comparison group. The rate of problems was much greater in the High Bias children with trisomies. Conclusions When advising parents after discovery of a trisomy, it is important to emphasise that, though there is an increased risk of language problems, there is a very wide range of outcomes. Severe language problems are more common in those identified via genetic testing for neurodevelopmental problems but these are not characteristic of children identified on prenatal screening.

Language phenotypes in children with sex chromosome trisomies

Background: Sex chromosome trisomies (47,XXX, 47,XXY and 47,XYY) are known to be a risk factor for language disorder, but typical outcomes are hard to estimate, because many cases are identified only when problems are found. Methods: We recruited children aged 5-16 years with all three types of trisomy, and divided them into a High Bias group, identified in the course of investigations for neurodevelopmental problems, and a Low Bias group, identified via prenatal screening or other medical investigations. Children from a twin sample were used to compare the pattern and severity of language problems: they were subdivided according to parental concerns about language/history of speech-language therapy into a No Concerns group (N = 132) and a Language Concerns group (N = 41). Children were individually assessed on a psychometric battery, and a standardized parent checklist. After excluding children with intellectual disability, autism or hearing problems, psychometric data were available for 31 XXX, 20 XXY and 19 XYY Low Bias cases and 13 XXX, 25 XXY and 32 XYY High Bias cases. Results: Variation within each trisomy group was substantial: within the Low Bias group, overall language scores were depressed relative to normative data, but around one-third had no evidence of problems. There was no effect of trisomy type, and the test profile was similar to the Language Concerns comparison group. The rate of problems was much greater in the High Bias children with trisomies. Conclusions: When advising parents after discovery of a trisomy, it is important to emphasise that, though there is an increased risk of language problems, there is a very wide range of outcomes. Severe language problems are more common in those identified via genetic testing for neurodevelopmental problems but these are not typical of children identified on prenatal screening.

Phonemic and Semantic Verbal Fluency in Sex Chromosome Aneuploidy: Contrasting the Effects of Supernumerary X versus Y Chromosomes on Performance

OBJECTIVES

Past research suggests that youth with sex chromosome aneuploidies (SCAs) present with verbal fluency deficits. However, most studies have focused on sex chromosome trisomies. Far less is known about sex chromosome tetrasomies and pentasomies. Thus, the current research sought to characterize verbal fluency performance among youth with sex chromosome trisomies, tetrasomies, and pentasomies by contrasting how performance varies as a function of extra X number and X versus Y status.

METHODS

Participants included 79 youth with SCAs and 42 typically developing controls matched on age, maternal education, and racial/ethnic background. Participants completed the phonemic and semantic conditions of a verbal fluency task and an abbreviated intelligence test.

RESULTS

Both supernumerary X and Y chromosomes were associated with verbal fluency deficits relative to controls. These impairments increased as a function of the number of extra X chromosomes, and the pattern of impairments on phonemic and semantic fluency differed for those with a supernumerary X versus Y chromosome. Whereas one supernumerary Y chromosome was associated with similar performance across fluency conditions, one supernumerary X chromosome was associated with relatively stronger semantic than phonemic fluency skills.

CONCLUSIONS

Verbal fluency skills in youth with supernumerary X and Y chromosomes are impaired relative to controls. However, the degree of impairment varies across groups and task condition. Further research into the cognitive underpinnings of verbal fluency in youth with SCAs may provide insights into their verbal fluency deficits and help guide future treatments. (JINS, 2018, 24, 917-927).