Genetic liability for gastrointestinal inflammation disorders and association with gastrointestinal symptoms in children with and without autism.

Children with autism spectrum disorder (ASD) have a greater prevalence of gastrointestinal (GI) symptoms than children without ASD. We tested whether polygenic scores for each of three GI disorders (ulcerative colitis, inflammatory bowel disease, and Crohn's disease) were related to GI symptoms in children with and without ASD. Using genotyping data (564 ASD cases and 715 controls) and external genome-wide association study summary statistics, we computed GI polygenic scores for ulcerative colitis (UC-PGS), inflammatory bowel disease (IDB-PGS), and Crohn's disease (CD-PGS). Multivariable logistic regression models, adjusted for genetic ancestry, were used to estimate associations between each GI-PGS and (1) ASD case-control status, and (2) specific GI symptoms in neurotypical children and separately in ASD children. In children without ASD, polygenic scores for ulcerative colitis were significantly associated with experiencing any GI symptom (adjusted odds ratio (aOR) = 1.36, 95% confidence interval (CI) = 1.03-1.81, p = 0.03) and diarrhea specifically (aOR = 5.35, 95% CI = 1.77-26.20, p = 0.01). Among children without ASD, IBD-PGS, and Crohn's PGS were significantly associated with diarrhea (aOR = 3.55, 95% CI = 1.25-12.34, p = 0.02) and loose stools alternating with constipation (aOR = 2.57, 95% CI = 1.13-6.55, p = 0.03), respectively. However, the three PGS were not associated with GI symptoms in the ASD case group. Furthermore, polygenic scores for ulcerative colitis significantly interacted with ASD status on presentation of any GI symptom within a European ancestry subset (aOR = 0.42, 95% CI = 0.19-0.88, p = 0.02). Genetic risk factors for some GI symptoms differ between children with and without ASD. Furthermore, our finding that increased genetic risks for GI inflammatory disorders are associated with GI symptoms in children without ASD informs future work on the early detection of GI disorders.

Many Young Children with Autism Who Use Psychotropic Medication Do Not Receive Behavior Therapy: A Multisite Case-Control Study.

OBJECTIVES: To explore how many pre-school aged children with autism spectrum disorder (ASD) used psychotropic medication, child and geographic factors associated with psychotropic medication use, and how many children who used psychotropic medication did or did not ever receive behavior therapy. STUDY DESIGN: Children 2-5 years of age were enrolled from 2012 to 2016 in a multisite case-control study designed to investigate the development and risk factors of ASD. Children with a positive ASD screen or ASD diagnosis upon enrollment were asked to complete a comprehensive evaluation to determine ASD status and developmental level. Caregivers completed a Services and Treatments Questionnaire and multiple self-administered questionnaires to determine child use of psychotropic medication, ever receipt of behavior therapy, and presence of co-occurring symptoms. RESULTS: There were 763 children who were classified as ASD and had data collected on the Services and Treatments Questionnaire. Of those, 62 (8.1%) used psychotropic medication to treat behavioral symptoms and 28 (3.7%) were ≤3 years of age when medication was first started. Attention problems (aOR, 7.65; 95% CI, 3.41-16.1; P < .001) and study site (aOR, 2.62; 95% CI, 1.04-6.56; P = .04) were significantly associated with psychotropic medication use after controlling for maternal race/ethnicity. More than one-half (59.7%) of those who used psychotropic medication did not ever receive behavior therapy. CONCLUSIONS: Many preschool-aged children with ASD who use psychotropic medication do not receive behavior therapy. Pediatricians are an important resource for children and families and can help facilitate behavioral treatment for children with ASD and other disorders.

Relationship of Weight Outcomes, Co-Occurring Conditions, and Severity of Autism Spectrum Disorder in the Study to Explore Early Development.

OBJECTIVE: To assess contributing factors to increased obesity risk, by comparing children with autism spectrum disorder (ASD), developmental delays/disorders, and general population controls in weight status, and to examine associations between weight status and presence of co-occurring medical, behavioral, developmental, or psychiatric conditions across groups and ASD severity among children with ASD. STUDY DESIGN: The Study to Explore Early Development is a multisite cross-sectional study of children, 2-5 years of age, classified as children with ASD (n = 668), children with developmental delays/disorders (n = 914), or general population controls (n = 884). Using an observational cohort design, we compared the 3 groups. Children's heights and weights were measured during a clinical visit. Co-occurring conditions (medical, behavioral, developmental/psychiatric) were derived from medical records, interviews, and questionnaires. ASD severity was measured by the Ohio State University Global Severity Scale for Autism. RESULTS: The odds of overweight/obesity were 1.57 times (95% CI 1.24-2.00) higher in children with ASD than general population controls and 1.38 times (95% CI 1.10-1.72) higher in children with developmental delays/disorders than general population controls. The aORs were elevated for children with ASD after controlling for child co-occurring conditions (ASD vs general population controls: aOR = 1.51; 95% CI 1.14-2.00). Among children with ASD, those with severe ASD symptoms were 1.7 times (95% CI 1.1-2.8) more likely to be classified as overweight/obese compared with children with mild ASD symptoms. CONCLUSIONS: Prevention of excess weight gain in children with ASD, especially those with severe symptoms, and in children with developmental delays/disorders represents an important target for intervention.

BMPR2 gene therapy for PAH acts via Smad and non-Smad signalling.

BACKGROUND AND OBJECTIVE: Pulmonary arterial hypertension (PAH) continues to be a fatal disease and is associated with downregulation of bone morphogenetic protein receptor type-2 (BMPR2). Our approach is to upregulate BMPR2 in the pulmonary vasculature allowing us to examine the changes in endothelial cell signalling and better understand what pathways are altered when disease is attenuated using this treatment approach. METHODS: We used gene delivery of BMPR2 to human pulmonary endothelial cells to investigate downstream signalling, then assessed the impact of this approach on downstream signalling in vivo in rats with PAH using the monocrotaline (MCT) model. RESULTS: Gene delivery of BMPR2 leads to an increase in BMPR2 protein expression, and this is associated with increased Smad1/5/8 and reduced Smad2/3 signalling. Additionally, we have found that BMPR2 modulation has effects on non-Smad signalling with increases found in phosphoinositide-3 kinase (PI3K) and a decrease in phosphorylated-p38-mitogen activated protein kinase (p38-MAPK) in vivo. These findings are associated with amelioration of PAH (reduced right ventricular, mean pulmonary artery pressures and Fulton Index). CONCLUSION: These results indicate that the therapeutic effect of BMPR2 gene delivery on PAH is associated with a switch between TGF-ß-Smad2/3 signalling to BMPR2-Smad1/5/8 signalling. This supports the further development of this treatment approach.

Sleep in Children With Autism Spectrum Disorders: How Are Measures of Parent Report and Actigraphy Related and Affected by Sleep Education?

Sleep disturbance is common in children with autism, resulting in a great need for effective treatments. To evaluate treatments for sleep disturbance in this population, it is critical to understand the relationship between measures of sleep captured by parent report and objective measures. The Children's Sleep Habits Questionnaire (CSHQ) and actigraphy-measured data from 80 children with autism and sleep-onset delay were evaluated. Reported problems with sleep-onset delay were concurrent with sleep duration problems in 66% of children, night wakings in 72% of children, and bedtime resistance in 66% of children; 38% of children were reported to have problems with all CSHQ insomnia domains. Actigraphy-measured sleep duration was correlated with estimates using CSHQ-reported bed and wake times.

Conducting actigraphy research in children with neurodevelopmental disorders--a practical approach.

The literature has been highly informative for when to use actigraphy and its validity in pediatric research. However, minimal literature exists on how to perform actigraphy, especially in special populations. We determined whether providing actigraphy training to parents and coordinators increased the nights of actigraphy data that could be scored. We compared two studies in children with autism spectrum disorders, one of which provided a basic level of training in a single-site trial and the other of which provided more detailed training to parents and coordinators in a multisite trial. There was an increase in scorable nights in the multisite trial containing a one-hour structured parent training session. Our results support the use of educational tools in clinical trials that use actigraphy.

Assessing Community Needs for Autism Spectrum Disorder: A Review of Rural/Frontier Needs Through Community Outreach With Developmental Pediatrics.

Early intervention is known to improve long-term outcomes for individuals with autism spectrum disorder (ASD). Access barriers to care limit timely engagement with supportive services. This report characterized the community needs and supportive services for children and families with suspected or diagnosed ASD. Families and providers participating in outreach clinics identified available services and their attitudes about support for ASD diagnosis. Chart reviews provided referral history, insurance, and current services. Children were nearly 6 years old, 95% of families relied on public health insurance, whereas 50% reported traveling 11 miles or greater for supportive services. Most providers (83%) were medically trained in primary care and placed 1-5 referrals per month to a tertiary referral hospital. Providers reported travel difficulty as the primary reason for referring patients for evaluation. Multiple barriers for supportive services were identified, highlighting the importance to increase the capacity and availability of local ASD supportive services.

Risk factors and clinical correlates of sensory dysfunction in preschool children with and without autism spectrum disorder.

Sensory dysfunction is a common feature of autism spectrum disorder (ASD). The objectives of this analysis were to examine risk factors and clinical correlates of sensory dysfunction in preschool children with and without ASD. Children aged 2-5 years were enrolled in a multi-site case-control study. Data were collected in eight areas across the United States in three phases. Caregivers completed an interview with questions on assisted delivery, maternal alcohol use, maternal anxiety during pregnancy, pregnancy weight gain, neonatal jaundice, preterm birth, and child sensory diagnosis given by a healthcare provider. Caregivers also completed an interview and questionnaires on sensory symptoms and clinical correlates of sensory dysfunction in their child. There were 2059 children classified as ASD, 3139 as other developmental delay or disability (DD), and 3249 as population comparison (POP). Caregivers reported significantly more sensory diagnoses and sensory symptoms in children classified as ASD than DD or POP (23.7%, 8.6%, and 0.8%, respectively, for a sensory diagnosis and up to 78.7% [ASD] vs. 49.6% [DD] for sensory symptoms). Maternal anxiety during pregnancy and neonatal jaundice were significantly associated with a sensory diagnosis and certain sensory symptoms in children with ASD and DD. Children's anxiety, attention deficits/hyperactivity, and sleep problems were significantly albeit subtly correlated with both a sensory diagnosis and sensory symptoms in children with ASD and DD. These findings support sensory dysfunction as a distinguishing symptom of ASD in preschool children and identify risk factors and clinical correlates to inform screening and treatment efforts in those with atypical development.

Toileting Resistance Among Preschool-Age Children with and Without Autism Spectrum Disorder.

OBJECTIVE: Children with autism spectrum disorder (ASD) may achieve continence later than other children. Little is known about factors associated with toileting resistance in children with ASD and other developmental delays/disabilities (DD). We sought to describe toileting resistance in children with ASD and DD and those from the general population (POP) and identify factors associated with toileting resistance in children with ASD and DD. METHOD: Families and children aged 24 to 68 months were enrolled in the Study to Explore Early Development, a multisite case-control study on ASD. Children with ASD (N = 743) and DD (N = 766) and those from the POP (N = 693) who were 48 months or older were included in this study. Parents reported toileting resistance, gastrointestinal issues, behavior problems, and ASD symptoms in their children. Children completed an in-person evaluation to determine ASD status and developmental level. RESULTS: Toileting resistance was more common among children with ASD (49.1%) than children with DD (23.6%) and those from the POP (8.0%). Diarrhea and deficits in social awareness were significantly associated with toileting resistance in children with ASD and DD. Constipation, expressive language delays, and low social motivation were significantly associated with toileting resistance only in children with ASD; very low visual reception skills and oppositional behaviors were significantly associated with toileting resistance in only children with DD (all p ≤ 0.05). CONCLUSION: Evaluating gastrointestinal issues, developmental delays, and social deficits before toileting training may help identify children with atypical development who are likely to present with toileting resistance. These evaluations can be incorporated into health supervision visits.

Compassion within an academic setting: Experiences of student nurses.

Compassion is fundamental to the delivery of quality nursing care and is an expected core competency that students must achieve to become a registered nurse. Nurse educators have a role in teaching compassion and in cultivating compassionate behaviours, among students, thus this novel study explores the student nurse's experience and understanding of compassion within the academic setting. A qualitative descriptive study using digitally recorded focus group interviews was undertaken with student nurses (n = 32) to explore their experiences of compassion in an academic setting. Data analysis was performed based on Braun and Clarke's framework of thematic analysis. Three themes were identified: students understanding of compassion, students experience of compassion within the academic setting and supporting compassion in an academic space. Student nurses reported their experiences of compassion as predominantly positive. They advocated for further 'space' within the curriculum for more formalised approaches to foster supportive relationships and to improve their experience of compassion within the academic setting. It is important to understand students' perspectives as this can guide teaching practice, organisational policy reform, and future research.

Providers' perspectives on the clinical utility of pharmacogenomic testing in pediatric patients.

Aim: To assess providers' knowledge, attitudes, perceptions, and experiences related to pharmacogenomic (PGx) testing in pediatric patients. Materials & methods: An electronic survey was sent to multidisciplinary healthcare providers at a pediatric hospital. Results: Of 261 respondents, 71.3% were slightly or not at all familiar with PGx, despite 50.2% reporting prior PGx education or training. Most providers, apart from psychiatry, perceived PGx to be at least moderately useful to inform clinical decisions. However, only 26.4% of providers had recent PGx testing experience. Unfamiliarity with PGx and uncertainty about the clinical value of testing were common perceived challenges. Conclusion: Low PGx familiarity among pediatric providers suggests additional education and electronic resources are needed for PGx examples in which data support testing in children.

Association between pica and gastrointestinal symptoms in preschoolers with and without autism spectrum disorder: Study to Explore Early Development.

BACKGROUND: Pica, the repeated ingestion of nonfood items, can result in gastrointestinal (GI) outcomes. Children with autism spectrum disorder (ASD) and other developmental disabilities (DDs) are disproportionately affected by both pica and GI symptoms. Study of the inter-relationship between pica, GI symptoms, and ASD/DD is limited. OBJECTIVE/HYPOTHESIS: We assessed associations between pica and GI symptoms in preschool-aged children with and without ASD and other (non-ASD) DDs in the Study to Explore Early Development. METHODS: Our sample included children with ASD (n = 1244), other DDs (n = 1593), and population (POP) controls (n = 1487). Data to define final case-control status, pica, and GI symptoms were from standardized developmental assessments/questionnaires. Prevalence ratios, adjusted for sociodemographic factors (aPRs), and 95% confidence intervals were derived from modified Poisson regression. RESULTS: Within each group (ASD, DD, POP) and for the total sample, pica was associated with vomiting (aPR for total sample 2.6 [1.7, 4.0]), diarrhea (1.8 [1.4, 2.2]), and loose stools (1.8 [1.4, 2.2]). In the DD group, pica was associated with constipation (1.4 [1.03, 1.9]) and pain on stooling (1.8 [1.2, 2.6]). In analyses of the subgroup without pica, increases in GI symptoms were still evident in the ASD and DD groups compared to POP group. CONCLUSION: These findings highlight an important adverse effect of pica, GI symptoms, in children with and without ASD and DDs; nonetheless, pica does not fully explain the increased risk for GI symptoms among children with ASD and DDs. These findings inform the specialized healthcare needs of children with ASD and other DDs.

Pica, Autism, and Other Disabilities.

BACKGROUND AND OBJECTIVES: Pica, the repeated ingestion of nonfood items, can be life-threatening. Although case reports describe pica in children with autism spectrum disorder (ASD) or intellectual disability (ID), there has been little systematic study of pica prevalence. We assessed pica in children 30 to 68 months of age (median = 55.4 months) with and without ASD. METHODS: Our sample from the Study to Explore Early Development, a multisite case-control study, included children with ASD (n = 1426), children with other developmental disabilities (DDs) (n = 1735), and general population-based controls (POPs) (n = 1578). We subdivided the ASD group according to whether children had ID and the DD group according to whether they had ID and/or some ASD characteristics. Standardized developmental assessments and/or questionnaires were used to define final study groups, subgroups, and pica. We examined pica prevalence in each group and compared ASD and DD groups and subgroups to the POP group using prevalence ratios adjusted for sociodemographic factors. RESULTS: Compared with the prevalence of pica among POPs (3.5%), pica was higher in children with ASD (23.2%) and DD (8.4%), and in the following subgroups: ASD with ID (28.1%), ASD without ID (14.0%), DD with ID (9.7%), DD with ASD characteristics (12.0%), and DD with both ID and ASD characteristics (26.3%); however, pica prevalence was not elevated in children with DD with neither ID nor ASD characteristics (3.2%). Between-group differences remained after adjustment (adjusted prevalence ratio range 1.9-8.0, all P <.05). CONCLUSIONS: Pica may be common in young children with ASD, ASD characteristics, and ID. These findings inform the specialized health care needs of these children.

Gastrointestinal Symptoms in 2- to 5-Year-Old Children in the Study to Explore Early Development.

Gastrointestinal symptoms (GIS) are commonly reported in children with autism spectrum disorder (ASD). This multi-site study evaluated the prevalence of GIS in preschool-aged children with ASD/(n = 672), with other developmental delays (DD)/(n = 938), and children in the general population (POP)/(n = 851). After adjusting for covariates, children in the ASD group were over 3 times more likely to have parent-reported GIS than the POP group, and almost 2 times more likely than the DD group. Children with GIS from all groups had more behavioral and sleep problems. Within the ASD group, children with developmental regression had more GIS than those without; however, there were no differences in autism severity scores between children with and without GIS. These findings have implications for clinical management.

Randomized, Placebo-Controlled Trial of Ferrous Sulfate to Treat Insomnia in Children With Autism Spectrum Disorders.

BACKGROUND: Insomnia and low iron stores are common in children with autism spectrum disorders, and low iron stores have been associated with sleep disturbance. METHODS: We performed a randomized placebo-controlled trial of oral ferrous sulfate to treat insomnia in children with autism spectrum disorders and low normal ferritin levels. Twenty participants who met inclusion criteria and whose insomnia did not respond to sleep education were randomized to 3 mg/kg/day of ferrous sulfate (n = 9) or placebo (n = 11) for three months. RESULTS: Iron supplementation was well tolerated, and no serious adverse events were reported. Iron supplementation improved iron status (+18.4 ng/mL active versus -1.6 ng/mL placebo, P = 0.044) but did not significantly improve the primary outcome measures of sleep onset latency (-11.0 minutes versus placebo, 95% confidence interval -28.4 to 6.4 minutes, P = 0.22) and wake time after sleep onset (-7.7 minutes versus placebo, 95% confidence interval -22.1 to 6.6 min, P = 0.29) as measured by actigraphy. Iron supplementation was associated with improvement in the overall severity score from the Sleep Clinical Global Impression Scale (-1.5 points versus placebo, P = 0.047). Changes in measures of daytime behavior did not differ between groups. CONCLUSION: This trial demonstrated no improvement in primary outcome measures of insomnia in subjects treated with ferrous sulfate compared with placebo. Interpretation was limited by low enrollment.

Does nutritional intake differ between children with autism spectrum disorders and children with typical development?

Consumption of macro- and micronutrients and food group servings by children with autism spectrum disorders (ASDs; n = 46) and typical development (n = 31) were compared using 3-day diet records. Children with ASDs consumed significantly more vitamin B6 and E and non-dairy protein servings, less calcium, and fewer dairy servings (p < .05). The significantly lower dairy serving intake persisted after controlling for child age and sex and parental dietary restrictions, and excluding children on the gluten-free casein-free (GFCF) diet. Large proportions of children in both groups did not meet national recommendations for daily intake of fiber, calcium, iron, vitamin E, and vitamin D.

Functional status of men with the fragile X premutation, with and without the tremor/ataxia syndrome (FXTAS).

BACKGROUND: Fragile X-associated tremor/ataxia syndrome (FXTAS), which occurs in some premutation carriers of the fragile X mental retardation 1 (FMR1) gene, is a neurodegenerative disorder characterized by action tremor, gait ataxia, and impaired executive cognitive functioning. OBJECTIVE: To evaluate the nature and severity of functional limitations among male carriers of the fragile X premutation, both with and without FXTAS. METHODS: Forty-two subjects with FXTAS and 24 asymptomatic premutation carriers were compared to 32 control subjects on measures of physical functioning, activities of daily living (ADLs; e.g. eating, bathing), and instrumental activities of daily living (IADLs; e.g. shopping, managing medications). Ordinary least squares regression, controlling for age, education, medical comorbidity, and pain, was used to examine group differences in physical and functional performance. RESULTS: Men with FXTAS performed significantly worse than control subjects on all dependent measures, showing greater limitations in physical functioning, as well as ADL and IADL performance (p < 0.05). Subsequent analyses suggested that physical and functional impairments among men with FXTAS result largely from deficits in motor and executive functioning and that CGG repeat length is associated with functional impairment. Asymptomatic carriers of the fragile X premutation performed similarly to control subjects on all measures. CONCLUSIONS: This study provides the first comprehensive evaluation of functional status among male premutation carriers. Although carriers without FXTAS performed similarly to control subjects, men with FXTAS showed evidence of significant physical and functional impairment, which appears to result largely from motor and executive deficits characteristic of the syndrome.

Infections in children with autism spectrum disorder: Study to Explore Early Development (SEED).

Immune system abnormalities have been widely reported among children with autism spectrum disorder (ASD), which may increase the risk of childhood infections. The Study to Explore Early Development (SEED) is a multisite case-control study of children aged 30-69 months, born in 2003-2006. Cases are children previously diagnosed and newly identified with ASD enrolled from education and clinical settings. Children with a previously diagnosed non-ASD developmental condition were included in the developmental delay/disorder (DD) control group. The population (POP) control group included children randomly sampled from birth certificates. Clinical illness from infection during the first 28 days ("neonatal," from medical records) and first three years of life (caregiver report) in cases was compared to DD and POP controls; and between cases with and without regression. Children with ASD had greater odds of neonatal (OR = 1.8; 95%CI: 1.1, 2.9) and early childhood infection (OR = 1.7; 95%CI: 1.5, 1.9) compared to POP children, and greater odds of neonatal infection (OR = 1.5; 95%CI: 1.1, 2.0) compared to DD children. Cases with regression had 1.6 times the odds (95%CI: 1.1, 2.3) of caregiver-reported infection during the first year of life compared to cases without regression, but neonatal infection risk and overall early childhood infection risk did not differ. Our results support the hypothesis that children with ASD are more likely to have infection early in life compared to the general population and to children with other developmental conditions. Future studies should examine the contributions of different causes, timing, frequency, and severity of infection to ASD risk. Autism Research 2019, 12: 136-146. © 2018 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: We looked at infections during early childhood in relation to autism spectrum disorder (ASD). We found that children with ASD were more likely to have an infection in the first 28 days of life and before age three compared to children with typical development. Children with ASD were also more likely than children with other developmental delays or disorders to have an infection in the first 28 days of life.

Sleep Problems in 2- to 5-Year-Olds With Autism Spectrum Disorder and Other Developmental Delays.

: media-1vid110.1542/5984243260001PEDS-VA_2018-0492Video Abstract BACKGROUND: Sleep problems can impact daytime behavior, quality of life, and overall health. We compared sleep habits in young children with autism spectrum disorder (ASD) and other developmental delays and disorders and in children from the general population (POP). METHODS: We included 2- to 5-year-old children whose parent completed all items on the Children's Sleep Habits Questionnaire (CSHQ) in a multisite case-control study: 522 children with ASD; 228 children with other developmental delays and disorders with autism spectrum disorder characteristics (DD w/ASD); 534 children with other developmental delays and disorders without autism spectrum disorder characteristics (DD w/o ASD); and 703 POP. Multivariable analysis of variance compared CSHQ mean total score (TS) and subscale scores between groups. Logistic regression analysis examined group differences by using TS cutoffs of 41 and 48. Analyses were adjusted for covariates. RESULTS: Mean CSHQ TS for children in each group: ASD (48.5); DD w/ASD (50.4); DD w/o ASD (44.4); and POP (43.3). Differences between children with ASD and both children with DD w/o ASD and POP were statistically significant. Using a TS cutoff of 48, the proportion of children with sleep problems was significantly higher in children in the ASD group versus DD w/o ASD and POP groups (adjusted odds ratios [95% confidence intervals]: 2.12 [1.57 to 2.87] and 2.37 [1.75 to 3.22], respectively). CONCLUSIONS: Sleep problems are more than twice as common in young children with ASD and DD w/ASD. Screening for sleep problems is important in young children to facilitate provision of appropriate interventions.

A new look at XXYY syndrome: medical and psychological features.

XXYY syndrome occurs in approximately 1:18,000-1:40,000 males. Although the physical phenotype is similar to 47,XXY (tall stature, hypergonadotropic hypogonadism, and infertility), XXYY is associated with additional medical problems and more significant neurodevelopmental and psychological features. We report on the results of a cross-sectional, multi-center study of 95 males age 1-55 with XXYY syndrome (mean age 14.9 years), describing diagnosis, physical features, medical problems, medications, and psychological features stratified by age groups. The mean age of diagnosis was 7.7 years. Developmental delays and behavioral problems were the most common primary indication for genetic testing (68.4%). Physical and facial features varied with age, although hypertelorism, clinodactyly, pes planus, and dental problems were common across all age groups. Tall stature was present in adolescents and adults, with a mean adult stature of 192.4 cm (SD 7.5; n = 22). Common medical problems included allergies and asthma (>50%), congenital heart defects (19.4%), radioulnar synostosis (17.2%), inguinal hernia and/or cryptorchidism (16.1%), and seizures (15%). Medical features in adulthood included hypogonadism (100%), DVT (18.2%), intention tremor (71%) and type II diabetes (18.2%). Brain MRI (n = 35) showed white matter abnormalities in 45.7% of patients and enlarged ventricles in 22.8%. Neurodevelopmental and psychological difficulties were a significant component of the behavioral phenotype, with developmental delays and learning disabilities universal but variable in severity. Twenty-six percent had full-scale IQs in the range of intellectual disability (MR), and adaptive functioning was significantly impacted with 68% with adaptive composite scores <70. Rates of neurodevelopmental disorders, including ADHD (72.2%), autism spectrum disorders (28.3%), mood disorders (46.8%), and tic disorders (18.9%), were elevated with 55.9% on psychopharmacologic medication overall. Recommendations for evaluation and treatment are summarized.