Increased prevalence of ADHD in Turner syndrome with no evidence of imprinting effects

Anxiety in Turner syndrome: Engaging community to address barriers and facilitators to diagnosis and care

Turner syndrome (TS), caused by complete or partial loss of the second sex chromosome, is associated with complex medical manifestations. The TS community identifies anxiety as a major contributor to reduced quality of life. The study aimed to improve understanding of anxiety symptomatology, diagnosis, and care in individuals with TS. A mixed methods design integrated community engagement, including community leaders as co-investigators and a community advisory board, an online survey (N = 135), and in-depth interviews (N = 10). The majority of respondents reported that anxiety symptoms occur two or more days per week, with self-advocates reporting more frequent symptoms than caregivers (p = 0.03). Self-advocates reported feeling anxious more often at school/work; both rater groups reported anxiety-related behaviors were most likely to be expressed at home. Insomnia was the most common symptom of anxiety endorsed across age and rater groups (>70%). Anxiety symptoms and triggers changed with age and often were undiagnosed or untreated during childhood. Therapy and medication were reported as helpful by most respondents who had tried these strategies. Qualitative themes included: 'Triggers for anxiety are related to TS', 'Anxiety impacts the whole family', and 'Opportunities for early identification and intervention'.

Clinical practice guidelines for the care of girls and women with Turner syndrome

Turner syndrome (TS) affects 50 per 100 000 females. TS affects multiple organs through all stages of life, necessitating multidisciplinary care. This guideline extends previous ones and includes important new advances, within diagnostics and genetics, estrogen treatment, fertility, co-morbidities, and neurocognition and neuropsychology. Exploratory meetings were held in 2021 in Europe and United States culminating with a consensus meeting in Aarhus, Denmark in June 2023. Prior to this, eight groups addressed important areas in TS care: (1) diagnosis and genetics, (2) growth, (3) puberty and estrogen treatment, (4) cardiovascular health, (5) transition, (6) fertility assessment, monitoring, and counselling, (7) health surveillance for comorbidities throughout the lifespan, and (8) neurocognition and its implications for mental health and well-being. Each group produced proposals for the present guidelines, which were meticulously discussed by the entire group. Four pertinent questions were submitted for formal GRADE (Grading of Recommendations, Assessment, Development and Evaluation) evaluation with systematic review of the literature. The guidelines project was initiated by the European Society for Endocrinology and the Pediatric Endocrine Society, in collaboration with members from the European Society for Pediatric Endocrinology, the European Society of Human Reproduction and Embryology, the European Reference Network on Rare Endocrine Conditions, the Society for Endocrinology, and the European Society of Cardiology, Japanese Society for Pediatric Endocrinology, Australia and New Zealand Society for Pediatric Endocrinology and Diabetes, Latin American Society for Pediatric Endocrinology, Arab Society for Pediatric Endocrinology and Diabetes, and the Asia Pacific Pediatric Endocrine Society. Advocacy groups appointed representatives for pre-meeting discussions and the consensus meeting.

High Prevalence of Obstructive Sleep-Disordered Breathing in Pediatric Patients With Turner Syndrome

OBJECTIVE

Girls with Turner syndrome (TS) often have features that have been associated with obstructive sleep-disordered breathing (oSDB). However, little is known about oSDB in TS. Herein, we aimed to characterize oSDB in young patients with TS and identify associated risk factors.

STUDY DESIGN

Retrospective cross-sectional study.

SETTING

Tertiary care pediatric hospital.

METHODS

We reviewed medical records for patients diagnosed with TS seen at our institution between October 1, 2007 and December 31, 2019 with the first outpatient visit before age 6 years. The prevalence of oSDB was compared to the general pediatric population with 1-sample binomial proportion tests. Clinical characteristics were compared between those diagnosed with oSDB and those without oSDB, and risk factors for oSDB were identified.

RESULTS

Of 151 patients with TS, 73 (48%) were diagnosed with oSDB which is 4-fold higher than the general pediatric population (12%, P < 0.0001). In the multivariable model, adenoid, tonsillar, and inferior turbinate hypertrophy, birthweight, failure to thrive, and older age at the last clinic visit were all associated with increased odds for oSDB.

CONCLUSION

Young children with TS have a high prevalence of oSDB and thus should be screened for oSDB. Polysomnography should be performed in those with associated risk factors and symptoms oSDB. Treatment of oSDB is imperative as individuals with TS are already at increased risk of behavioral problems, neurocognitive deficits, and growth impairment that may be worsened with oSDB.

Neuropsychological and mental health concerns in a multicenter clinical sample of youth with turner syndrome

Clinical practice guidelines for individuals with Turner syndrome (TS) recommend screening for neuropsychological concerns (NC) and mental health concerns (MHC). However, current provider screening and referral patterns for NC and MHC are not well characterized. Additionally, prevalence of and risk factors for NC and MHC vary across studies. This multicenter chart review study examined the prevalence, risk factors for, and management of NC and MHC in a cohort of 631 patients with TS from three pediatric academic medical centers. NC and/or MHC were documented for 48.2% of patients. Neuropsychological evaluation recommendations were documented for 33.9% of patients; 65.4% of the sample subsequently completed these evaluations. Mental health care recommendations were documented in 35.0% of records; subsequent documentation indicated that 69.7% of these patients received such services. Most notably, rates of documented MHC, NC, and related referrals differed significantly by site, suggesting the need for standardized screening and referral practices. TS diagnosis in early childhood was associated with an increased risk of NC. Spontaneous menarche was associated with increased risk of MHC. Younger age at growth hormone initiation was associated with both increased risk of isolated NC and co-occurring NC and MHC. Mosaic karyotype was associated with decreased risk of NC and MHC.

Longitudinal investigation of cognition, social competence, and anxiety in children and adolescents with Turner syndrome

Turner syndrome (TS), a common neurogenetic disorder caused by complete or partial absence of an X chromosome in females, is characterized by distinct physical, cognitive, and social-emotional features. Girls with TS typically display average overall intellectual functioning with relative strength in verbal abilities and weaknesses in visuospatial processing, executive function (EF), and social cognition. This study was designed to better understand longitudinal trajectories of cognitive and social-emotional domains commonly affected in TS. Participants included 57 girls with monosomic 45,X TS and 55 age- and verbal-IQ matched girls who completed behavioral, child-report, and parent-report measures across four timepoints. Group differences in visuospatial processing, EF, social cognition, and anxiety were assessed longitudinally. Potential effects of estrogen replacement therapy (ERT) were assessed cross-sectionally on an exploratory basis. The TS group showed poorer performance on measures of visuospatial processing, EF, and social cognition, but not anxiety, compared to controls throughout childhood and adolescence. There were no significant group differences in the trajectory of skill development over time. Exploratory analyses within the TS group revealed that girls who were receiving ERT showed better performance on measures of overall IQ, expressive vocabulary, and visuospatial processing compared to those not receiving ERT. Consistent with existing literature, weaknesses in visuospatial processing, EF, and social competence among girls with TS persisted throughout childhood and adolescence. Exploratory analyses suggest that ERT may help improve some aspects of cognitive function in TS, although other pre-existing, nonhormonal differences between the two TS subgroups may alternatively explain these findings, given our study design. Future studies are needed to examine potential impacts of ERT on cognitive and social-emotional development in TS.

Mental health and neurodevelopment in children and adolescents with Turner syndrome

OBJECTIVES

Turner syndrome (TS) is a rare sex chromosome aneuploidy, with an incidence of four in 10,000 new-born girls. TS is often associated with impaired social communication skills, but the extent to which these are attributable to Autism Spectrum Disorders (ASD) is uncertain. We made standardized assessments of the mental health and associated neurodevelopmental disorders in children and adolescents with TS and report on the prevalence of concurrent conditions.

METHODS

Our sample comprised 127 girls with TS, 5-19 years of age. We obtained reports of their mental health from a combination of diagnostic interview (the Development and Wellbeing Assessment (DAWBA)), from the Strengths and Difficulties Questionnaire (SDQ) and from the Social Responsiveness Scale (SRS-2). Sources of information included parents, teachers and self-reports. The prevalence of mental health disorders in this sample was compared with age/sex matched national English data from typical controls.

RESULTS

Most individuals with TS (83%) had experienced significant social communication difficulties and nearly one in four (23%) met diagnostic criteria for ASD on the DAWBA. One-third (34%) had at least one mental health or neurodevelopmental condition, and those girls with an ASD were at a greater risk of a co-occurring emotional disorder and/or attention deficit hyperactivity disorder (ADHD).

CONCLUSION

Children and adolescents with TS are substantially more likely to meet criteria for ASD than their typically developing peers. Our finding has clinical implications for appropriate behavioural management from preschool through to adolescence.

PGCLCs of human 45,XO reveal pathogenetic pathways of neurocognitive and psychosocial disorders

Background

Neurocognitive disorders and psychosocial difficulties are common in patients with Turner syndrome and multiple neurodegenerative diseases, yet there is no effective cure. Human primordial germ cells (hPGCs) are pluripotent germline stem cells in early embryo, which pass genetic information from one generation to the next, whereas all somatic cells will die along with the end of life. However, it is not known whether patient hPGCs with Turner syndrome contain information of neurocognitive and psychosocial illness.

Results

In this report, we used a high-density of culture system of embryoids derived from iPSCs of a patient with Turner syndrome to ask how pathogenetic pathways are associated with onset of neurocognitive and psychosocial disorders. The hPGC-Like Cells (hPGCLCs) were in vitro specified from iPSCs of 45,XO, 46,XX and 46,XY by the high-density induction of embryoids. Amazingly, we found that the specification process of the hPGCLCs in 45,XO, compared to those in 46,XX and 46,XY, enriched several common pathogenetic pathways regulating neurocognitive and psychosocial disorders, that shared among multiple neurodegenerative diseases and Turner syndrome. The downregulated chemical synaptic transmission pathways, including glutamatergic, GABAergic, and nicotine cholinergic synapses, indicated synaptic dysfunctions, while upregulated pathways that were associated with imbalance of mitochondrial respiratory chain complexes and apoptosis, may contribute to neuronal dysfunctions. Notably, downregulation of three types of ubiquitin ligases E1-E2-E3 and lysosome-associated sulfatases and RAB9A, owing to haploinsufficiency and parental preference of the X chromosome expression, indicated that two pathways of cellular degradation, lysosome and ubiquitin–proteasome, were impaired in the specification process of 45,XO hPGCLCs. This would lead to accumulation of undesired proteins and aggregates, which is a typically pathological hallmark in neurodegenerative diseases.

Conclusions

Our data suggest that the specification process of the hPGCLCs in 45,XO, compared to those in 46,XX and 46,XY, enriched pathogenetic pathways that are associated with the onset of neurocognitive and psychosocial disorders.

Chromosomal and environmental contributions to sex differences in the vulnerability to neurological and neuropsychiatric disorders: Implications for therapeutic interventions

Neurological and neuropsychiatric disorders affect men and women differently. Multiple sclerosis, Alzheimer's disease, anxiety disorders, depression, meningiomas and late-onset schizophrenia affect women more frequently than men. By contrast, Parkinson's disease, autism spectrum condition, attention-deficit hyperactivity disorder, Tourette's syndrome, amyotrophic lateral sclerosis and early-onset schizophrenia are more prevalent in men. Women have been historically under-recruited or excluded from clinical trials, and most basic research uses male rodent cells or animals as disease models, rarely studying both sexes and factoring sex as a potential source of variation, resulting in a poor understanding of the underlying biological reasons for sex and gender differences in the development of such diseases. Putative pathophysiological contributors include hormones and epigenetics regulators but additional biological and non-biological influences may be at play. We review here the evidence for the underpinning role of the sex chromosome complement, X chromosome inactivation, and environmental and epigenetic regulators in sex differences in the vulnerability to brain disease. We conclude that there is a pressing need for a better understanding of the genetic, epigenetic and environmental mechanisms sustaining sex differences in such diseases, which is critical for developing a precision medicine approach based on sex-tailored prevention and treatment.

Novel insights in Turner syndrome

PURPOSE OF REVIEW

Turner syndrome is the most common sex chromosome abnormality in female individuals, affecting 1/2000-1/2500 female newborns. Despite the high incidence of this condition, the mechanisms underlying the development of multiorgan dysfunction have not been elucidated.

RECENT FINDINGS

Clinical features involve multiple organ systems and include short stature, dysmorphic facial features, delayed puberty and gonadal failure, cardiac and renal abnormalities, audiologic abnormalities, and a high prevalence of endocrine and autoimmune disorders. Paucity of available genotype/phenotype correlation limits the ability of clinicians to provide accurate guidance and management. Given the advent of robust genetic testing and analysis platforms, developments in the genetic basis of disease are materializing at a rapid pace.

SUMMARY

The objective of this review is to highlight the recent advances in knowledge and to provide a framework with which to apply new data to the foundational understanding of the condition.

Effect of sex chromosome number variation on attention-deficit/hyperactivity disorder symptoms, executive function, and processing speed

AIM

To study sex differences in attention-deficit/hyperactivity disorder (ADHD) symptoms, we explored whether X chromosome absence or excess is independently associated with deficits in attention and hyperactivity, executive function, and processing speed.

METHOD

We assessed 116 children (ages 3y 10mo-11y 11mo, mean 8y 5mo, SD 1y 11mo) with a variable number of sex chromosomes: 36 females with Turner syndrome (45, X0), 20 males with Klinefelter syndrome (47, XXY), 37 typically developing females (XX), and 23 typically developing males (XY).

RESULTS

X chromosome absence was associated with increased attention problems, hyperactivity, and deficits in inhibitory control, compared with female children with XX (all p<0.003). Conversely, X chromosome excess was associated with weakness in working memory (p=0.018) and approached significance for attention problems (p=0.071) but not with hyperactivity, or weakness in inhibitory control relative to male children with XY. Using non-parametric effect size to quantify the clinical effect revealed that X chromosome absence affected attention, hyperactivity, executive function, and processing speed (all r>0.4), while X excess affected in-laboratory as well as parent-reported working memory (all r>0.4).

INTERPRETATION

Our observations provide compelling evidence that the absence or excess of an X chromosome distinctly affects cognition and behaviors associated with ADHD.

Neurodegenerative Disease: Roles for Sex, Hormones, and Oxidative Stress

Neurodegenerative diseases cause severe impairments in cognitive and motor function. With an increasing aging population and the onset of these diseases between 50 and 70 years, the consequences are bound to be devastating. While age and longevity are the main risk factors for neurodegenerative diseases, sex is also an important risk factor. The characteristic of sex is multifaceted, encompassing sex chromosome complement, sex hormones (estrogens and androgens), and sex hormone receptors. Sex hormone receptors can induce various signaling cascades, ranging from genomic transcription to intracellular signaling pathways that are dependent on the health of the cell. Oxidative stress, associated with aging, can impact the health of the cell. Sex hormones can be neuroprotective under low oxidative stress conditions but not in high oxidative stress conditions. An understudied sex hormone receptor that can induce activation of oxidative stress signaling is the membrane androgen receptor (mAR). mAR can mediate nicotinamide adenine dinucleotide-phosphate (NADPH) oxidase (NOX)-generated oxidative stress that is associated with several neurodegenerative diseases, such as Alzheimer disease. Further complicating this is that aging can alter sex hormone signaling. Prior to menopause, women experience more estrogens than androgens. During menopause, this sex hormone profile switches in women due to the dramatic ovarian loss of 17β-estradiol with maintained ovarian androgen (testosterone, androstenedione) production. Indeed, aging men have higher estrogens than aging women due to aromatization of androgens to estrogens. Therefore, higher activation of mAR-NOX signaling could occur in menopausal women compared with aged men, mediating the observed sex differences. Understanding of these signaling cascades could provide therapeutic targets for neurodegenerative diseases.

Turner Syndrome and the Risks of Clinical Depression in Adolescence

According to the Center for Disease Control (CDC), 3.2% of children aged 3-17 years have been diagnosed with depression. Many genetic conditions predispose children and adolescents to various mental health problems. Turner syndrome is a common sporadic genetic condition in females with medical issues, developmental delays, and psychiatric comorbidities. There is limited literature about adolescents with a late diagnosis of Turner syndrome and struggles with affective psychopathology. The early recognition and understanding of its unique genetics, neurobiology, and specific clinical manifestations are critical for addressing the needs of these patients.

Neurodevelopmental and psychiatric disorders in females with Turner syndrome: a population-based study

Background

Turner syndrome is the result of the partial or complete absence of an X chromosome in phenotypic girls. This can cause an array of medical and developmental difficulties. The intelligence quotient in females with Turner syndrome has previously been described as uneven, but considered within normal range. Although their social, intellectual, and psychiatric profile is described, it is unclear to what extent these females meet the clinical criteria for neurodevelopmental or psychiatric diagnoses. The aim of this study was to examine the prevalence of neurodevelopmental and psychiatric disorders in females with Turner syndrome.

Methods

A retrospective cohort study was performed with a total of 1392 females with Turner syndrome identified through the Swedish National Patient Register and compared with 1:100 age- and sex-matched controls from the general population. The associations between Turner syndrome and diagnoses of neurodevelopmental and/or psychiatric disorders were calculated using conditional logistic regression and is presented as estimated risk (odds ratio, OR, 95% confidence interval, CI) in females with Turner syndrome compared with matched controls.

Results

Females with Turner syndrome had a higher risk of neurodevelopmental or psychiatric disorder (OR 1.37, 95% CI 1.20–1.57), an eightfold increased risk of intellectual disability (OR 8.59, 95% CI 6.58–11.20), and a fourfold increased risk of autism spectrum disorder (OR 4.26, 95% CI 2.94‑6.18) compared with the controls. In addition, females with Turner syndrome had twice the risk of a diagnosis of schizophrenia and related disorders (OR 1.98, 95% CI 1.36–2.88), eating disorders (OR 2.03, 95% CI 1.42–2.91), and behavioral and emotional disorders with onset in childhood (OR 2.01, 95% CI 1.35–2.99).

Conclusions

Females with Turner syndrome have an increased risk of receiving a diagnosis of neurodevelopmental or psychiatric disorder. This warrants extensive assessment of intellectual and cognitive functions from early age, and increased psychiatric vigilance should be a part of lifelong healthcare for females with Turner syndrome.

Altered Brain Structure in Infants with Turner Syndrome

Turner syndrome (TS) is a genetic disorder affecting approximately 1:2000 live-born females. It results from partial or complete X monosomy and is associated with a range of clinical issues including a unique cognitive profile and increased risk for certain behavioral problems. Structural neuroimaging studies in adolescents, adults, and older children with TS have revealed altered neuroanatomy but are unable to identify when in development differences arise. In addition, older children and adults have often been exposed to years of growth hormone and/or exogenous estrogen therapy with potential implications for neurodevelopment. The study presented here is the first to test whether brain structure is altered in infants with TS. Twenty-six infants with TS received high-resolution structural MRI scans of the brain at 1 year of age and were compared to 47 typically developing female and 39 typically developing male infants. Results indicate that the typical neuroanatomical profile seen in older individuals with TS, characterized by decreased gray matter volumes in premotor, somatosensory, and parietal-occipital cortex, is already present at 1 year of age, suggesting a stable phenotype with origins in the prenatal or early postnatal period.

Effects of X Chromosome Monosomy and Genomic Imprinting on Observational Markers of Social Anxiety in Prepubertal Girls with Turner Syndrome

Previous studies have suggested that girls with Turner syndrome (TS) exhibit symptoms of social anxiety during interactions with others. However, few studies have quantified these behaviors during naturalistic face-to-face social encounters. In this study, we coded observational markers of social anxiety in prepubertal girls with TS and age-matched controls during a 10-min social encounter with an unfamiliar examiner. Results showed that girls with TS exhibited significantly higher levels of gaze avoidance compared to controls. Impairments in social gaze were particularly increased in girls with a maternally retained X chromosome (Xm), suggesting a genomic imprinting effect. These data indicate that social gaze avoidance may be a critical behavioral marker for identifying early social dysfunction in young girls with TS.

The contribution of Xp22.31 gene dosage to Turner and Klinefelter syndromes and sex-biased phenotypes

Turner syndrome (TS) is a rare developmental condition in females caused by complete, or partial, loss of the second sex chromosome; it is associated with a number of phenotypes including short stature, ovarian failure and infertility, as well as neurobehavioural and cognitive manifestations. In contrast, Klinefelter syndrome (KS) arises from an excess of X chromosome material in males (typical karyotype is 47,XXY); like TS, KS is associated with infertility and hormonal imbalance, and behavioural/neurocognitive differences from gonadal sex-matched counterparts. Lower dosage of genes that escape X-inactivation may partially explain TS phenotypes, whilst overdosage of these genes may contribute towards KS-related symptoms. Here, I discuss new findings from individuals with deletions or duplications limited to Xp22.31 (a region escaping X-inactivation), and consider the extent to which altered gene dosage within this small interval (and of the steroid sulfatase (STS) gene in particular) may influence the phenotypic profiles of TS and KS. The expression of X-escapees can be higher in female than male tissues; I conclude by considering how lower Xp22.31 gene dosage in males may increase their likelihood of exhibiting particular phenotypes relative to females. Understanding the genetic contribution to specific phenotypes in rare disorders such as TS and KS, and to more common sex-biased phenotypes, will be important for developing more effective, and more personalised, therapeutic approaches.

Mental Health Disorders in Children With Congenital Heart Disease

BACKGROUND

Data on anxiety, depression, and attention-deficit/hyperactivity disorder (ADHD) are lacking for youth with congenital heart disease (CHD), particularly those with simple CHD. This study aims to characterize these disorders in youth with CHD compared to those without CHD.

METHODS

A comparative cross-sectional study was conducted by using the electronic medical records of a large tertiary care hospital between 2011 and 2016. Inclusion criteria were youth aged 4 to 17 years with >1 hospitalization or emergency department visits. Exclusion criteria were patients with arrhythmias or treatment with clonidine and/or benzodiazepines. The primary predictor variable was CHD type: simple, complex nonsingle ventricle, and complex single ventricle. The primary outcome variable was a diagnosis and/or medication for anxiety and/or depression or ADHD. Data were analyzed by using logistic regression (Stata v15; Stata Corp, College Station, TX).

RESULTS

We identified 118 785 patients, 1164 with CHD. Overall, 18.2% (n = 212) of patients with CHD had a diagnosis or medication for anxiety or depression, compared with 5.2% (n = 6088) of those without CHD. All youth with CHD had significantly higher odds of anxiety and/or depression or ADHD. Children aged 4 to 9 years with simple CHD had ∼5 times higher odds (odds ratio: 5.23; 95% confidence interval: 3.87-7.07) and those with complex single ventricle CHD had ∼7 times higher odds (odds ratio: 7.46; 95% confidence interval: 3.70-15.07) of diagnosis or treatment for anxiety and/or depression. Minority and uninsured youth were significantly less likely to be diagnosed or treated for anxiety and/or depression or ADHD, regardless of disease severity.

CONCLUSIONS

Youth with CHD of all severities have significantly higher odds of anxiety and/or depression and ADHD compared to those without CHD. Screening for these conditions should be considered in all patients with CHD.

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.

Early Development of Infants with Turner Syndrome

OBJECTIVE

To examine the early cognitive, temperament, and adaptive functioning of infants and toddlers with Turner syndrome (TS).

METHODS

Cognitive abilities were measured using the Mullen Scales of Early Learning at 1 year of age for 31 girls with TS and compared with neurotypical female (N = 53) and male (N = 54) control groups. Temperament (Carey Toddler Temperament Scales) and adaptive functioning (Vineland Adaptive Behavior Scales-Second Edition) were measured at 1 year of age and compared with normative data. An exploratory analysis of cognitive/developmental trajectories was also conducted comparing age 12-month to 24-month time points for 22 TS subjects.

RESULTS

Infants with TS performed largely within the average range for adaptive behavior, temperament, and early cognitive development with some increased risk for delays in language and significant increased risk for delays in motor skills (p < 0.001). Although exploratory, there was some suggestion of slower rates of progression in fine-motor and visual reception skills from 12 to 24 months of age.

CONCLUSIONS

Infants and toddlers with TS exhibit a relatively positive neurodevelopmental profile overall, with some indication of an increasing gap in function in fine-motor and visual perceptual abilities as compared to neurotypical peers. It is unclear whether these apparent differences represent normal variability in this very young population or, perhaps, are early precursors of later phenotypic characteristics of TS in the school-age and young adult years.

Cognitive Functioning in Turner Syndrome: Addressing Deficits Through Academic Accommodation

Background: The cognitive profile of Turner syndrome, a genetic disorder resulting from partial or complete X-chromosome deletion, presents characteristic deficits. Despite this, studies have yet to evaluate how deficits translate into and are compensated for in academic settings. This study seeks to explore cognitive functioning, as well as the accessibility and development of academic accommodations in females with Turner syndrome from adolescence to adulthood. Materials and Methods: This cross-sectional study took place at the National Institutes of Health. Females with Turner syndrome (age range: 10-68; n = 142) were evaluated on need for and procurement of academic accommodations. Cognitive functioning was evaluated in participants aged 20 years and older (n = 101), as per the age validation of the Repeatable Battery for the Assessment of Neuropsychological Status. Data were analyzed using descriptive statistics, one-sample comparisons, and analyses of variance. Results: Females with Turner syndrome scored significantly lower than the normative population on visuospatial (p < 0.001), delayed memory (p < 0.001), and overall (p < 0.001) functioning. About 25.9% of participants reported that accommodations were not needed, despite displaying one or more cognitive deficits. Approximately 12.7% reported needing but not receiving accommodations, however, this is only reported by females 30 years and older; no females aged 10-29 years indicated this discrepancy. Conclusions: Findings suggest that procurement of academic accommodations has increased within recent decades. Still, there is a discrepancy between those displaying cognitive deficits and those receiving academic accommodations. We highlight frequently received accommodations so that students and professionals can target deficits with appropriate accommodations.

X-Chromosome Effects on Attention Networks: Insights from Imaging Resting-State Networks in Turner Syndrome

Attention deficit hyperactivity disorder (ADHD) is strongly affected by sex, but sex chromosomes' effect on brain attention networks and cognition are difficult to examine in humans. This is due to significant etiologic heterogeneity among diagnosed individuals. In contrast, individuals with Turner syndrome (TS), who have substantially increased risk for ADHD symptoms, share a common genetic risk factor related to the absence of the X-chromosome, thus serving as a more homogeneous genetic model. Resting-state functional MRI was employed to examine differences in attention networks between girls with TS (n = 40) and age- sex- and Tanner-matched controls (n = 33). We compared groups on resting-state functional connectivity measures from data-driven independent components analysis (ICA) and hypothesis-based seed analysis. Using ICA, reduced connectivity was observed in both frontoparietal and dorsal attention networks. Similarly, using seeds in the bilateral intraparietal sulcus (IPS), reduced connectivity was observed between IPS and frontal and cerebellar regions. Finally, we observed a brain-behavior correlation between IPS-cerebellar connectivity and cognitive attention measures. These findings indicate that X-monosomy contributes affects to attention networks and cognitive dysfunction that might increase risk for ADHD. Our findings not only have clinical relevance for girls with TS, but might also serve as a biological marker in future research examining the effects of the intervention that targets attention skills.

Developmental trajectories of motor skills during the preschool period

Children with developmental coordination disorder also manifest difficulties in non-motor domains (attentional, emotional, behavioral and socialization skills). Longitudinal studies can help disentangle the complex relationships between the development of motor skills and other cognitive domains. This study aims to examine the contribution of early cognitive factors to changes in motor skills during the preschool period. Children (N = 1144) from the EDEN mother-child cohort were assessed for motor skills with the Copy Design task (NEPSY battery) and the parent-rated Ages and Stages Questionnaire (fine and gross motor skills scores) at ages 3 and 5-6 years. At 3 years, language skills were evaluated using tests from the NEPSY and ELOLA batteries. Emotional problems, conduct problems, inattention and hyperactivity symptoms, peer relationships and pro-social behavior were assessed with the Strengths and Difficulties Questionnaire (SDQ) also at 3 years. Linear and logistic regression models were performed to examine whether positive and negative changes in motor skills between 3 and 5-6 years are associated with specific cognitive skills at 3 years, while adjusting for a broad range of pre- and postnatal environmental factors. In the linear regression model, the SDQ Inattention symptoms score at 3 years was associated with negative changes in motor skills (standardized β = - 0.09, SD = 0.03, p value = 0.007) and language skills at 3 years were associated with positive changes in motor skills (standardized β = 0.05, SD = 0.02, p value = 0.041) during the preschool period. In logistic regression models, the SDQ Inattention symptoms score at 3 years was associated with a higher likelihood of a declining trajectory of motor skills (OR [95% CI] = 1.37 [1.02-1.84]). A higher language skills score at 3 years was associated with an increased likelihood of a resilient trajectory (1.67 [1.17-2.39]). This study provides a better understanding of the natural history of developmental coordination delays by identifying cognitive factors that predict changes in motor skills between the ages of 3 and 5-6 years.

Reversal Learning Performance in the XY∗ Mouse Model of Klinefelter and Turner Syndromes

Klinefelter syndrome (KS; 47, XXY) and Turner syndrome (TS; 45, XO) are caused by two relatively common sex chromosome aneuploidies. These conditions are associated with an increased odds of neuropsychiatric disorders, including attention deficit/hyperactivity disorder (ADHD), as well as impairments in cognition that include learning delays, attentional dysfunction and impulsivity. We studied cognitive functions in the XY^∗ mouse model, which allows comparison of XXY to XY males (KS model), and XO to XX females (TS model). We evaluated adult mice with and without gonads, using a version of an operant reversal-learning task (RLT) that can be used to measure various facets of learning, impulsivity and attention. In the KS model, only one measure related to impulsivity – perseverative responding under reversal conditions – reliably discriminated gonadally intact XXY and XY mice. In contrast, a fundamental learning impairment (more trials to criterion in acquisition phase) in XXY mice, as compared to XY, was observed in gonadectomized subjects. No other task measures showed differences consistent with KS. In the TS mouse model, XO mice did not show a pattern of results consistent with TS, similar to past observations. Thus, the application of this RLT to these XY^∗ models reveals only limited behavioral impairments relevant to KS.

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.

Recognition and management of adults with Turner syndrome: From the transition of adolescence through the senior years

Turner syndrome is recognized now as a syndrome familiar not only to pediatricians and pediatric specialists, medical geneticists, adult endocrinologists, and cardiologists, but also increasingly to primary care providers, internal medicine specialists, obstetricians, and reproductive medicine specialists. In addition, the care of women with Turner syndrome may involve social services, and various educational and neuropsychologic therapies. This article focuses on the recognition and management of Turner syndrome from adolescents in transition, through adulthood, and into another transition as older women. It can be viewed as an interpretation of recent international guidelines, complementary to those recommendations, and in some instances, an update. An attempt was made to provide an international perspective. Finally, the women and families who live with Turner syndrome and who inspired several sections, are themselves part of the broad readership that may benefit from this review.

Clinical developmental, neuropsychological, and social-emotional features of Turner syndrome

Individuals with Turner syndrome (TS) are at risk for a constellation of neurocognitive and psychosocial differences, although there is significant individual variability in these features. TS is associated with an increased risk for difficulties with visual-spatial reasoning, visual-spatial memory, attention, executive functioning, motor, and math skills. Additionally, increased rates of social difficulties, anxiety, and depression are observed. There can be significant interplay between all of these factors contributing to the behavioral phenotype. Neuropsychological features and previous research are reviewed. Clinical considerations and recommendations for evaluation and treatment of psychological and behavioral difficulties are provided, including consideration of medical features in TS, as well as therapies, educational supports, and medication treatment. Future research is needed to evaluate effectiveness of different treatments for neuropsychological and psychosocial features of TS, including modification and validation of existing evidence-based treatments and new approaches to care.

Sex differences in psychiatric disorders: what we can learn from sex chromosome aneuploidies

The study of sexual dimorphism in psychiatric and neurodevelopmental disorders is challenging due to the complex interplay of diverse biological, psychological, and social factors. Males are more susceptible to neurodevelopmental disorders including intellectual disability, autism spectrum disorder, and attention-deficit activity disorder. Conversely, after puberty, females are more prone to major depressive disorder and anxiety disorders compared to males. One major biological factor contributing to sex differences is the sex chromosomes. First, the X and Y chromosomes have unique and specific genetic effects as well as downstream gonadal effects. Second, males have one X chromosome and one Y chromosome, while females have two X chromosomes. Thus, sex chromosome constitution also differs between the sexes. Due to this complexity, determining genetic and downstream biological influences on sexual dimorphism in humans is challenging. Sex chromosome aneuploidies, such as Turner syndrome (X0) and Klinefelter syndrome (XXY), are common genetic conditions in humans. The study of individuals with sex chromosome aneuploidies provides a promising framework for studying sexual dimorphism in neurodevelopmental and psychiatric disorders. Here we will review and contrast four syndromes caused by variation in the number of sex chromosomes: Turner syndrome, Klinefelter syndrome, XYY syndrome, and XXX syndrome. Overall we describe an increased rate of attention-deficit hyperactivity disorder and autism spectrum disorder, along with the increased rates of major depressive disorder and anxiety disorders in one or more of these conditions. In addition to contributing unique insights about sexual dimorphism in neuropsychiatric disorders, awareness of the increased risk of neurodevelopmental and psychiatric disorders in sex chromosome aneuploidies can inform appropriate management of these common genetic disorders.

Sex: A Significant Risk Factor for Neurodevelopmental and Neurodegenerative Disorders

Males and females sometimes significantly differ in their propensity to develop neurological disorders. Females suffer more from mood disorders such as depression and anxiety, whereas males are more susceptible to deficits in the dopamine system including Parkinson's disease (PD), attention-deficit hyperactivity disorder (ADHD) and autism. Despite this, biological sex is rarely considered when making treatment decisions in neurological disorders. A better understanding of the molecular mechanism(s) underlying sex differences in the healthy and diseased brain will help to devise diagnostic and therapeutic strategies optimal for each sex. Thus, the aim of this review is to discuss the available evidence on sex differences in neuropsychiatric and neurodegenerative disorders regarding prevalence, progression, symptoms and response to therapy. We also discuss the sex-related factors such as gonadal sex hormones and sex chromosome genes and how these might help to explain some of the clinically observed sex differences in these disorders. In particular, we highlight the emerging role of the Y-chromosome gene, SRY, in the male brain and its potential role as a male-specific risk factor for disorders such as PD, autism, and ADHD in many individuals.

Sex chromosome abnormalities and psychiatric diseases

Excesses of sex chromosome abnormalities in patients with psychiatric diseases have recently been observed. It remains unclear whether sex chromosome abnormalities are related to sex differences in some psychiatric diseases. While studies showed evidence of susceptibility loci over many sex chromosomal regions related to various mental diseases, others demonstrated that the sex chromosome aneuploidies may be the key to exploring the pathogenesis of psychiatric disease. In this review, we will outline the current evidence on the interaction of sex chromosome abnormalities with schizophrenia, autism, ADHD and mood disorders.

Clinical practice guidelines for the care of girls and women with Turner syndrome: proceedings from the 2016 Cincinnati International Turner Syndrome Meeting

Turner syndrome affects 25-50 per 100,000 females and can involve multiple organs through all stages of life, necessitating multidisciplinary approach to care. Previous guidelines have highlighted this, but numerous important advances have been noted recently. These advances cover all specialty fields involved in the care of girls and women with TS. This paper is based on an international effort that started with exploratory meetings in 2014 in both Europe and the USA, and culminated with a Consensus Meeting held in Cincinnati, Ohio, USA in July 2016. Prior to this meeting, five groups each addressed important areas in TS care: 1) diagnostic and genetic issues, 2) growth and development during childhood and adolescence, 3) congenital and acquired cardiovascular disease, 4) transition and adult care, and 5) other comorbidities and neurocognitive issues. These groups produced proposals for the present guidelines. Additionally, four pertinent questions were submitted for formal GRADE (Grading of Recommendations, Assessment, Development and Evaluation) evaluation with a separate systematic review of the literature. These four questions related to the efficacy and most optimal treatment of short stature, infertility, hypertension, and hormonal replacement therapy. The guidelines project was initiated by the European Society for Endocrinology and the Pediatric Endocrine Society, in collaboration with The European Society for Pediatric Endocrinology, The Endocrine Society, European Society of Human Reproduction and Embryology, The American Heart Association, The Society for Endocrinology, and the European Society of Cardiology. The guideline has been formally endorsed by the European Society for Endocrinology, the Pediatric Endocrine Society, the European Society for Pediatric Endocrinology, the European Society of Human Reproduction and Embryology and the Endocrine Society. Advocacy groups appointed representatives who participated in pre-meeting discussions and in the consensus meeting.

Attention deficit hyperactivity disorder (ADHD) in phenotypically similar neurogenetic conditions: Turner syndrome and the RASopathies

Background

ADHD (attention deficit hyperactivity disorder) is a common neurodevelopmental disorder. There has been extensive clinical and basic research in the field of ADHD over the past 20 years, but the mechanisms underlying ADHD risk are multifactorial, complex and heterogeneous and, as yet, are poorly defined. In this review, we argue that one approach to address this challenge is to study well-defined disorders to provide insights into potential biological pathways that may be involved in idiopathic ADHD.

Main body

To address this premise, we selected two neurogenetic conditions that are associated with significantly increased ADHD risk: Turner syndrome and the RASopathies (of which Noonan syndrome and neurofibromatosis type 1 are the best-defined with regard to ADHD-related phenotypes). These syndromes were chosen for two main reasons: first, because intellectual functioning is relatively preserved, and second, because they are strikingly phenotypically similar but are etiologically distinct. We review the cognitive, behavioural, neural and cellular phenotypes associated with these conditions and examine their relevance as a model for idiopathic ADHD.

Conclusion

We conclude by discussing current and future opportunities in the clinical and basic research of these conditions, which, in turn, may shed light upon the biological pathways underlying idiopathic ADHD.

Care of girls and women with Turner syndrome: beyond growth and hormones

Turner syndrome (TS), although considered a rare disease, is the most common sex chromosome abnormality in women, with an incident of 1 in 2500 female births. TS is characterized by distinctive physical features such as short stature, ovarian dysgenesis, an increased risk for heart and renal defects as well as a specific cognitive and psychosocial phenotype. Given the complexity of the condition, patients face manifold difficulties which increase over the lifespan. Furthermore, failures during the transitional phase to adult care result in moderate health outcomes and decreased quality of life. Guidelines on the optimal screening procedures and medical treatment are easy to find. However, recommendations for the treatment of the incriminating psychosocial aspects in TS are scarce. In this work, we first reviewed the literature on the cognitive and psychosocial development of girls with TS compared with normal development, from disclosure to young adulthood, and then introduce a psychosocial approach to counseling and treating patients with TS, including recommendations for age-appropriate psychological diagnostics. With this work, we aim to facilitate the integration of emphasized psychosocial care in state-of-the-art treatment for girls and women with TS.

Overview: referrals for genetic evaluation from child psychiatrists

A growing multitude of known genetic diagnoses can result in presentation to child psychiatry. For numerous reasons, it is important to identify a genetic etiology in child psychiatry patients when it is present. Genetic diagnoses can guide treatment and enable access to specialized clinics and appropriate screening measures. They can also allow for genetic counseling for the patient and family. A better understanding of etiology with a named diagnosis can itself be of great value to many patients and families; prognostic information can be empowering. Since patients with genetic conditions may present to psychiatric care in diverse ways, child psychiatrists must decide who to refer for genetic evaluation. Here we create a table to provide a framework of concerning/notable history and exam features that a practicing child psychiatrist may encounter that should prompt one to consider whether a larger, unifying genetic diagnosis is at hand. We hope this framework will facilitate referral of child psychiatry patients to genetics so that more patients can benefit from an appropriate diagnosis.

Elucidating X chromosome influences on Attention Deficit Hyperactivity Disorder and executive function

OBJECTIVE

To identify distinct behavioral and cognitive profiles associated with ADHD in Turner syndrome (TS), relative to idiopathic ADHD and neurotypical controls, in order to elucidate X-linked influences contributing to ADHD.

METHODS

We used a multilevel-model approach to compare 49 girls with TS to 37 neurotypical females, aged 5-12, on established measures of behavior (BASC-2) and neurocognitive function (NEPSY). We further compared girls with TS to BASC-2 and NEPSY age-matched reference data obtained from children with idiopathic ADHD.

RESULTS

Within the TS group, 51% scored at or above the "at-risk" range for ADHD-associated behaviors on the BASC-2 (TS/+ADHD). The BASC-2 behavioral profile in this TS/+ADHD-subgroup was comparable to a reference group of boys with ADHD with respect to attentional problems and hyperactivity. However, the TS/+ADHD-subgroup had significantly higher hyperactivity scores relative to a reference sample of girls with ADHD (p = 0.016). The behavioral profile in TS was associated with significantly lower attention and executive function scores on the NEPSY relative to neurotypical controls (p = 0.015); but was comparable to scores from a reference sample of children with idiopathic ADHD. Deficits in attention and executive function were not observed in girls with TS having low levels of ADHD-associated behavior (TS/-ADHD).

CONCLUSIONS

ADHD-associated behavioral and cognitive problems in TS are prevalent and comparable in severity to those found in children with idiopathic ADHD. The ADHD phenotype in TS also appears relatively independent of cognitive features typically associated with TS, like visuospatial weaknesses. These findings suggest that X-linked haploinsufficiency and downstream biological effects contribute to increased risk for ADHD.

Emotional and behavioral problems in late-identified Indonesian patients with disorders of sex development

OBJECTIVE

The aim of this study is to investigate emotional and behavioral problems among Indonesian patients with disorders of sex development (DSD) who recently came under clinical management. As diagnostic procedures and treatment had been delayed, patients progressively developed ambiguous bodies, difficult to conceal from outsiders.

METHOD

We compared 118 Indonesian patients with DSD aged 6-41 years (60 children, 24 adolescents, 34 adults) and 118 healthy control subjects matched for age, gender, and residential settings. We used the Child Behavioral Checklist (CBCL), Youth Self-Report (YSR), and Adult Self-Report (ASR) to examine differences between patient and control groups as well as differences within patients groups.

RESULTS

On the CBCL, parents of young children with DSD reported significantly more emotional and behavioral problems than parents of matched control. Parents of daughters with CAH reported that their daughters withdrew themselves from social interactions. On the ASR, adults with DSD reported significantly more internalizing problems than controls, particularly anxiety and depression. No other differences in emotional functioning were found across different diagnostic groups.

CONCLUSIONS

Indonesian patients with DSD who were untreated for most of their lives suffered more emotional and behavioral problems than matched controls. Differences and similarities between our findings and observations in patients from Western countries will be discussed.

What we do not know about ADHD… yet

PURPOSE OF REVIEW

This article provides an overview of current controversies in attention-deficit/hyperactivity disorder (ADHD) research, with an emphasis on recent findings that are directly relevant to clinical practice.

RECENT FINDINGS

Over the past few years, a number of studies have added key evidence to ongoing debates about the epidemiology, nosology, and treatment of ADHD. Although the causes of the rising prevalence of ADHD in the USA are still not fully understood, recent research suggests that environmental factors and changes to the diagnostic criteria may have played a role. In addition, there continues to be controversy surrounding the clinical diagnosis of ADHD and newly recognized, related conditions such as sluggish cognitive tempo. Recent studies have also challenged previous assumptions about the long-term effects of stimulant treatment on growth, academic achievement, and substance use. Moreover, although most complementary and alternative therapies for ADHD appear to be ineffective, there is emerging evidence supporting the value of fatty acid supplementation. Although these findings are promising, more research is needed on all fronts.

SUMMARY

Although research has shed light on unanswered questions about the epidemiology, nosology, and treatment of ADHD, much is still not known. An understanding of the most important current controversies in ADHD research may aid pediatricians in clinical decision making and allow them to counsel patients more effectively.

Biological factors underlying sex differences in neurological disorders

The prevalence, age of onset, pathophysiology, and symptomatology of many neurological and neuropsychiatric conditions differ significantly between males and females. Females suffer more from mood disorders such as depression and anxiety, whereas males are more susceptible to deficits in the dopamine system including Parkinson's disease (PD), attention-deficit hyperactivity disorder (ADHD), schizophrenia, and autism spectrum disorders (ASD). Until recently, these sex differences have been explained solely by the neuroprotective actions of sex hormones in females. Emerging evidence however indicates that the sex chromosome genes (i.e. X- and Y-linked genes) also contribute to brain sex differences. In particular, the Y-chromosome gene, SRY (Sex-determining Region on the Y chromosome) is an interesting candidate as it is expressed in dopamine-abundant brain regions, where it regulates dopamine biosynthesis and dopamine-mediated functions such as voluntary movement in males. Furthermore, SRY expression is dysregulated in a toxin-induced model of PD, suggesting a role for SRY in the pathogenesis of dopamine cells. Taken together, these studies highlight the importance of understanding the interplay between sex-specific hormones and sex-specific genes in healthy and diseased brain. In particular, better understanding of regulation and function of SRY in the male brain could provide entirely novel and important insights into genetic factors involved in the susceptibility of men to neurological disorders, as well as development of novel sex-specific therapies.

Stimulant use and its impact on growth in children receiving growth hormone therapy: an analysis of the KIGS International Growth Database

BACKGROUND

Children receiving stimulants for attention deficit hyperactivity disorder (ADHD) frequently present to pediatric endocrinology clinics for evaluation and treatment of growth disorders. The worldwide prevalence of stimulant use in children with ADHD also receiving recombinant human growth hormone (rhGH) and the impact on response to rhGH are unknown.

METHODS

Data on children enrolled in the KIGS® (Pfizer International Growth Study) registry were evaluated for the associated diagnosis of ADHD prior to initiation of Genotropin® rhGH. Concomitant stimulant medications and auxological information were captured. Response to rhGH was evaluated using established growth prediction models.

RESULTS

The prevalence of ADHD in KIGS was 2.3% (1,748/75,251), with stimulants used in 1.8% (1,326/75,251). Children with idiopathic growth hormone deficiency (IGHD) who received stimulants grew significantly less (1.1 cm) in the first year of rhGH therapy than expected for rhGH-treated non-ADHD IGHD children. After one year of rhGH, idiopathic short stature (ISS) children with ADHD were significantly shorter [0.74 cm (with stimulants) and 0.69 cm (without stimulants)] than non-ADHD ISS children.

CONCLUSIONS

We demonstrated an impaired response to rhGH in IGHD and ISS children with ADHD. Our findings suggest that the ADHD phenotype, alone or in conjunction with stimulant therapy, may impair the short-term growth response to rhGH.

Annual research review: Rare genotypes and childhood psychopathology--uncovering diverse developmental mechanisms of ADHD risk

BACKGROUND

Through the increased availability and sophistication of genetic testing, it is now possible to identify causal diagnoses in a growing proportion of children with neurodevelopmental disorders. In addition to developmental delay and intellectual disability, many genetic disorders are associated with high risks of psychopathology, which curtail the wellbeing of affected individuals and their families. Beyond the identification of significant clinical needs, understanding the diverse pathways from rare genetic mutations to cognitive dysfunction and emotional-behavioural disturbance has theoretical and practical utility.

METHODS

We overview (based on a strategic search of the literature) the state-of-the-art on causal mechanisms leading to one of the most common childhood behavioural diagnoses - attention deficit hyperactivity disorder (ADHD) - in the context of specific genetic disorders. We focus on new insights emerging from the mapping of causal pathways from identified genetic differences to neuronal biology, brain abnormalities, cognitive processing differences and ultimately behavioural symptoms of ADHD.

FINDINGS

First, ADHD research in the context of rare genotypes highlights the complexity of multilevel mechanisms contributing to psychopathology risk. Second, comparisons between genetic disorders associated with similar psychopathology risks can elucidate convergent or distinct mechanisms at each level of analysis, which may inform therapeutic interventions and prognosis. Third, genetic disorders provide an unparalleled opportunity to observe dynamic developmental interactions between neurocognitive risk and behavioural symptoms. Fourth, variation in expression of psychopathology risk within each genetic disorder points to putative moderating and protective factors within the genome and the environment.

CONCLUSION

A common imperative emerging within psychopathology research is the need to investigate mechanistically how developmental trajectories converge or diverge between and within genotype-defined groups. Crucially, as genetic predispositions modify interaction dynamics from the outset, longitudinal research is required to understand the multi-level developmental processes that mediate symptom evolution.

Number of X-chromosome genes influences social behavior and vasopressin gene expression in mice

Sex differences in behavior are widespread and often caused by hormonal differences between the sexes. In addition to hormones, the composition and numbers of the sex chromosomes also affect a variety of sex differences. In humans, X-chromosome genes are implicated in neurobehavioral disorders (i.e. fragile-X, autism). To investigate the role of X-chromosome genes in social behavior, we used a mouse model that has atypical sex chromosome configurations resembling Turner (45, XO) and Klinefelter syndromes (47, XXY). We examined a number of behaviors in juvenile mice. Mice with only one copy of most X-chromosome genes, regardless of gonadal sex, were less social in dyadic interaction and social preference tasks. In the elevated plus maze, mice with one X-chromosome spent less time in the distal ends of the open arms as compared to mice with two copies of X-chromosome genes. Using qRTPCR, we noted that amygdala from female mice with one X-chromosome had higher expression levels of vasopressin (Avp) as compared to mice in the other groups. Finally, in plasma from girls with Turner syndrome we detected reduced vasopressin (AVP) concentrations as compared to control patients. These novel findings link sex chromosome genes with social behavior via concentrations of AVP in brain, adding to our understanding of sex differences in neurobehavioral disorders.

Why the Diagnosis of Attention Deficit Hyperactivity Disorder Matters

BACKGROUND

Attention Deficit Hyperactivity disorder (ADHD) is one of the most common and challenging childhood neurobehavioral disorders. ADHD is known to negatively impact children, their families, and their community. About one-third to one-half of patients with ADHD will have persistent symptoms into adulthood. The prevalence in the United States is estimated at 5-11%, representing 6.4 million children nationwide. The variability in the prevalence of ADHD worldwide and within the US may be due to the wide range of factors that affect accurate assessment of children and youth. Because of these obstacles to assessment, ADHD is under-diagnosed, misdiagnosed, and undertreated.

OBJECTIVES

We examined factors associated with making and receiving the diagnosis of ADHD. We sought to review the consequences of a lack of diagnosis and treatment for ADHD on children's and adolescent's lives and how their families and the community may be involved in these consequences.

METHODS

We reviewed scientific articles looking for factors that impact the identification and diagnosis of ADHD and articles that demonstrate naturalistic outcomes of diagnosis and treatment. The data bases PubMed and Google scholar were searched from the year 1995 to 2015 using the search terms "ADHD, diagnosis, outcomes." We then reviewed abstracts and reference lists within those articles to rule out or rule in these or other articles.

RESULTS

Multiple factors have significant impact in the identification and diagnosis of ADHD including parents, healthcare providers, teachers, and aspects of the environment. Only a few studies detailed the impact of not diagnosing ADHD, with unclear consequences independent of treatment. A more significant number of studies have examined the impact of untreated ADHD. The experience around receiving a diagnosis described by individuals with ADHD provides some additional insights.

CONCLUSION

ADHD diagnosis is influenced by perceptions of many different members of a child's community. A lack of clear understanding of ADHD and the importance of its diagnosis and treatment still exists among many members of the community including parents, teachers, and healthcare providers. More basic and clinical research will improve methods of diagnosis and information dissemination. Even before further advancements in science, strong partnerships between clinicians and patients with ADHD may be the best way to reduce the negative impacts of this disorder.

Sex differences in attention Deficit Hyperactivity Disorder: candidate genetic and endocrine mechanisms

Attention Deficit Hyperactivity Disorder (ADHD) is a developmental condition characterised by severe inattention, pathological impulsivity and hyperactivity; it is relatively common affecting up to 6% of children, and is associated with a risk of long-term adverse educational and social consequences. Males are considerably more likely to be diagnosed with ADHD than females; the course of the disorder and its associated co-morbidities also appear to be sensitive to sex. Here, I discuss fundamental biological (genetic and endocrine) mechanisms that have been shown to, or could theoretically, contribute towards these sexually dimorphic phenomena. Greater understanding of how and why the sexes differ with respect to ADHD vulnerability should allow us to identify and characterise novel protective and risk factors for the disorder, and should ultimately facilitate improved diagnosis, prognosis and treatment.

Influence of the X-chromosome on neuroanatomy: evidence from Turner and Klinefelter syndromes

Studies of sex effects on neurodevelopment have traditionally focused on animal models investigating hormonal influences on brain anatomy. However, more recent evidence suggests that sex chromosomes may also have direct upstream effects that act independently of hormones. Sex chromosome aneuploidies provide ideal models to examine this framework in humans, including Turner syndrome (TS), where females are missing one X-chromosome (45X), and Klinefelter syndrome (KS), where males have an additional X-chromosome (47XXY). As these disorders essentially represent copy number variants of the sex chromosomes, investigation of brain structure across these disorders allows us to determine whether sex chromosome gene dosage effects exist. We used voxel-based morphometry to investigate this hypothesis in a large sample of children in early puberty, to compare regional gray matter volumes among individuals with one (45X), two (typically developing 46XX females and 46XY males), and three (47XXY) sex chromosomes. Between-group contrasts of TS and KS groups relative to respective sex-matched controls demonstrated highly convergent patterns of volumetric differences with the presence of an additional sex chromosome being associated with relatively decreased parieto-occipital gray matter volume and relatively increased temporo-insular gray matter volumes. Furthermore, z-score map comparisons between TS and KS cohorts also suggested that this effect occurs in a linear dose-dependent fashion. We infer that sex chromosome gene expression directly influences brain structure in children during early stages of puberty, extending our understanding of genotype-phenotype mechanisms underlying sex differences in the brain.

Turner syndrome: review of clinical, neuropsychiatric, and EEG status: an experience of tertiary center

We reviewed the clinical, neuropsychiatric, and EEG status of 53 turner syndrome (TS) females, aged 3-16 years, in Assiut university hospitals, Upper Egypt. The diagnosis and care of patients with TS in Egypt is still in the developing stage. Hence this study was undertaken to review the details of patients with TS with respect to the pattern of cognitive, psychiatric, and motor dysfunction. We aimed to provide a comprehensive data about the experience of our center comparable to previous studies, which have been published in this field. This will contribute to a better definition of the neuropsychiatric features that may be specific to TS that allows early and better detection and management of these cases. We found FSIQ and verbal IQ that seem to be at a nearly normal level and a decreased performance IQ. ADHD and autistic symptoms were found in 20.70 and 3.77 % of our cohort, respectively. The motor performance in TS was disturbed, with some neurological deficits present in 17 % (reduced muscle tone and reduced muscle power). In addition, females with TS in our study exhibit social and emotional problems, including anxiety (5.66 %) and depression (11.30 %). The EEG results revealed abnormalities in seven patients (13.20 %). One patient presenting with generalized tonic-clonic seizures showed generalized epileptiform activity, and six patients presenting with intellectual disabilities showed abnormal EEG background activity.

Effect of the parental origin of the X-chromosome on the clinical features, associated complications, the two-year-response to growth hormone (rhGH) and the biochemical profile in patients with turner syndrome

Background

It is possible that genes on the X chromosome are expressed differently depending of its parental origin. The objective of this study was to determine the influence of the parental origin of the X-chromosome on phenotypic variability, response to rhGH and on the biochemical profile of TS patients.

Methods

This was a cross-sectional multicenter correlational study carried out over three years in six Latin-American university hospitals. Unrelated 45,X TS patients (n =  93; 18.3 ± 8.5 years )) were evaluated. A subgroup (n =  34) of the patients were prospectively treated with rhGH over two years. DNA profiles of patients and their mothers were compared to determine the parental origin of the retained X-chromosome through 10 polymorphic X-chromosome-STRs. The association with clinical features, biochemical profiles and anthropometric data at the beginning and after two years of rhGH treatment was determined.

Results

Seventy two percent of patients retained the maternal X chromosome (Xm). A trend towards significance between maternal height and patients final height (p ≤ 0.07) in 45,Xm subjects was observed. There was no correlation between paternal height and patient height. No differences were detected between both groups in regard to dysmorphic features, classical malformations or increase in the height-SDS after rhGH. There were higher levels of triglycerides, total and LDL cholesterol in patients >20 years who retained the Xm.

Conclusions

The parental origin of the retained X chromosome may influence lipid metabolism in TS patients, but its effect on growth seems to be minimal. No parental-origin-effect on the phenotypic features, associated anomalies and on the growth response to rhGH was found in 45,X TS individuals.