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Lattice-matched graphene on hexagonal boron nitride is expected to lead to the formation of a band-gap but requires the formation of highly strained material and has not hitherto been realised. We demonstrate that aligned, lattice-matched graphene can be grown by molecular beam epitaxy using substrate temperatures in the range 1600-1710 °C and co-exists with a topologically-modified moiré pattern, and with regions of strained graphene which have giant moiré periods up to ~80 nm. Raman spectra reveal narrow red-shifted peaks due to isotropic strain, while the giant moiré patterns result in complex splitting of Raman peaks due to strain variations across the moiré unit cell. The lattice-matched graphene has a lower conductance than both the Frenkel-Kontorova-type domain walls, and also the topological defects where they terminate. We relate these results to theoretical models of band-gap formation in graphene/boron nitride heterostructures.

47,XXY (KS) occurs in 1:650 male births, though less than 25% are ever identified. We assessed stability of neurocognitive features across diverse populations and quantified factors mediating outcome. Forty‐four boys from the Netherlands (NL) and 54 boys from the United States (US) participated. The Wechsler Intelligence Scales assessed intellectual functioning; the ANT program evaluated cognitive function; and the CBCL assessed behavioral functioning. ANOVA was used for group comparisons. Hierarchical regressions assessed variance explained by each independent variable: parental education, timing of diagnosis, testosterone, age, and nationality. Parental education, timing of diagnosis, and hormonal treatment all played an important role in neurocognitive performance. The observed higher IQ and better attention regulation in the US group as compared to the NL group was observed with decreased levels of behavioral problems in the US group. Cognitive measures that were different between the NL and US groups, i.e., attention regulation and IQ scores, were also significantly influenced by external factors including timing of diagnosis, testosterone treatment, and parental education. On the ANT, a cognitive phenotype of 47,XXY was observed, with similar scores on 9 out of the 10 ANT subtests for the NL and US groups. This study lays additional features to the foundation for an algorithm linking external variables to outcome on various neurodevelopmental measures.

The aim of the study was to examine the impact of familial learning disabilities (FLD) on the phenotypic profile of 47, XXY (Klinefelter syndrome) males and the possibility that 47, XXY males with more severe cognitive deficits may be partially a consequence of familial dyslexia/reading disorder. We wondered if FLD could pose an additional risk for complex neurodevelopmental differences in 47, XXY. The neurodevelopmental profile of males with 47, XXY has been characterized by developmental dyspraxia, language-based learning disorders, executive dysfunction, reading, and attentional deficits. One hundred eighteen boys with 47, XXY diagnosed prenatally who did not receive early hormonal treatment were divided into two groups based on positive histories of FLD and given comprehensive neurodevelopmental evaluations between 36 and 108 months. The assessments included intelligence (nonverbal and verbal), neuromotor (fine and gross), speech, and language. The group with FLD performed significantly lower in multiple neurodevelopmental domains of the Wechsler of VIQ P = 0.015, FSIQ P = 0.0005, the Brief IQ P = 0.0525 of the Leiter, in Auditory Comprehension P = 0.0505, Expressive Communication P = 0.0055, and neuromotor domains of Manual Coordination P = 0.0032, Fine Motor Control P = 0.0378, and Motor Coordination P = 0.008. Our study demonstrates the influence of FLD on neurodevelopment and expands the phenotypic profile of 47, XXY, suggesting some neurodevelopmental variability is attributable to other factors than the additional X. FLD may increase the vulnerability of the 47, XXY children and anticipatory guidance should be provided to families. © 2014 Wiley Periodicals, Inc. Language: en

Studies have shown an increased head circumference and the absence of the head tilt reflex as possible risk factors for autism spectrum disorder, allowing for early detection at 12 months in typically developing population of infants. Our aim was to develop a screening tool to identify infants prior to 12 months at risk for autism spectrum disorder and developmental learning delay, not affected by literacy or primary parental language, and provide immediate determination of risk for autism spectrum disorder. An abrupt head circumference acceleration and the absence of head tilt reflex by 9 months were used to identify infants at risk for autism spectrum disorder. Stability of early findings was then investigated when compared to comprehensive standardized neurodevelopmental assessment results and complete neurological and genetics evaluations. A total of 1024 typically developing infants were enrolled by 9 months, with 14 identified as at risk for autism spectrum disorder and 33 for developmental learning delay. There was a good positive predictive value for the identification of autism spectrum disorder prior to 12 months. This study demonstrates an efficient means to identify infants at risk for autism spectrum disorder by 9 months of age and serves to alert primary care providers of infants who are vulnerable for autism spectrum disorder before symptoms are discernible by clinical judgment of primary care providers, parental concerns, or by screening questionnaires.

49, XXXXY is a rare aneuploidy and variant of Klinefelter syndrome, occurring in 1 per 80,000-100,000 live births. We present a cohort of 40 affected males, focusing on musculoskeletal problems. Subjects were participants in an annual 49er family support group meeting. Children were examined in a multidisciplinary clinic by a pediatric neurologist and geneticist, a pediatric orthopedist, a neurodevelopmentalist, and two physical therapists. The patient data were collected from this clinic from 2004 to 2012. All patients were required to have karyotypes that confirmed the presence of XXXXY. There was a high prevalence of musculoskeletal disorders, particularly hypotonia (34 patients [85%]), radioulnar synostosis (30 [75%]), pes planus (26 [65%]), asymmetric hip rotation (27 [67.5%]), and clinodactyly (24 [60%]). Other, less common lower-extremity disorders, included, 5 patients (12.5%) with unilateral club foot, 5 boys (12.5%) with pes cavus, 10 patients (25%) genu valgum and 2 children with genu varus (5%). To our knowledge, this is the first large cohort of boys with 49, XXXXY that focuses on musculoskeletal disorders. There was an increased incidence of hypotonia, clubfoot, avascular necrosis of the femoral head, radioulnar synostosis, and pes planus compared to the normative population. Boys with 49, XXXXY would benefit from multidisciplinary evaluations, particularly from pediatric orthopedists, physical therapists, neurologists, and geneticists for appropriate medical care.

47, XXY occurs in up to 1 in 650 male births and is associated with androgen deficiency, neurodevelopmental delays, and atypical social-behaviors. Previously, we showed that young boys with 47, XXY who received early hormonal therapy (EHT) had significantly improved neurodevelopment. The objective of this follow-up study was to examine the effects of EHT on social behavior in boys with 47, XXY. The study consisted of boys prenatally diagnosed with 47, XXY who were referred for evaluations. Twenty-nine boys received three injections of 25 mg testosterone enanthate and 57 controls did not receive EHT. Behavioral functioning was assessed using the Behavior Rating Inventory of Executive Function, Social Responsiveness Scale, 2nd Ed., and the Child Behavior Checklist for Ages 6–18. The hypothesis that EHT may affect behavior was formulated prior to data collection. Questionnaire data was prospectively obtained and analyzed to test for significance between two groups. Significant differences were identified between group's scores over time in Social Communication (P = 0.007), Social Cognition (P = 0.006), and Total T-score (P = 0.001) on the SRS-2; Initiation (P = 0.05) on the BRIEF; and Externalizing Problems (P = 0.024), Affective Problems (P = 0.05), and Aggressive Behaviors (P = 0.031) on the CBCL. This is the third study revealing positive effects of EHT on boys with XXY. There was a significant improvements associated with the 47, XXY genotype in boys who received EHT. Research is underway on the neurobiological mechanisms, and later developmental effects of EHT. © 2015 Wiley Periodicals, Inc.

Kleefstra syndrome (KS) is a rare neurogenetic disorder most commonly caused by deletion in the 9q34.3 chromosomal region and is associated with intellectual disabilities, severe speech delay, and motor planning deficits. To our knowledge, this is the first patient (PQ, a 6-year-old female) with a 9q34.3 deletion who has near normal intelligence, and developmental dyspraxia with childhood apraxia of speech (CAS). At 6, the Wechsler Preschool and Primary Intelligence testing (WPPSI-III) revealed a Verbal IQ of 81 and Performance IQ of 79. The Beery Buktenica Test of Visual Motor Integration, 5th Edition (VMI) indicated severe visual motor deficits: VMI = 51; Visual Perception = 48; Motor Coordination < 45. On the Receptive One Word Picture Vocabulary Test-R (ROWPVT-R), she had standard scores of 96 and 99 in contrast to an Expressive One Word Picture Vocabulary-R (EOWPVT-R) standard scores of 73 and 82, revealing a discrepancy in vocabulary domains on both evaluations. Preschool Language Scale-4 (PLS-4) on PQ's first evaluation reveals a significant difference between auditory comprehension and expressive communication with standard scores of 78 and 57, respectively, further supporting the presence of CAS. This patient's near normal intelligence expands the phenotypic profile as well as the prognosis associated with KS. The identification of CAS in this patient provides a novel explanation for the previously reported speech delay and expressive language disorder. Further research is warranted on the impact of CAS on intelligence and behavioral outcome in KS. Therapeutic and prognostic implications are discussed.

The behavioral phenotype of children with XXY has not been extensively studied until recently and this research has been confounded by insufficient study populations and ascertainment biases. The aim of the study was to expand the behavioral aspect of the XXY phenotype as well as investigate the role of existing familial learning disabilities (FLD) on behavioral problems. Behavioral phenotype of XXY includes social anxiety, ADHD, social communication, and atypical peer interactions. The Child Behavior Checklist (CBCL), Social Responsiveness Scale (SRS), and Gilliam Autism Rating Scale (GARS) were completed by the parents of 54 boys with XXY who had not received hormonal replacement prior to participation. Our findings suggest fewer behavioral deficits and lower severity in the general 47,XXY population than previously published and found significant differences between the groups with a positive FLD on the behavioral assessments. Findings demonstrate that boys with FLD exhibit an increased incidence and severity of behavioral problems. Our study expands on the findings of Samango-Sprouse et al. [Samango-Sprouse et al. (2012b) J Intellect Disabil Res] and the significant influence that FLD has on not only neurodevelopment, but also behavioral deficits. Our study suggests that part of the XXY phenotypic profile may be modulated by FLD. Further study is underway to examine the interaction between the many salient factors effecting behavioral and neurodevelopmental progression in XXY and variant forms. © 2013 Wiley Periodicals, Inc.

The effects of early androgen treatment on neurodevelopmental performance in pre-pubertal boys with 47,XXY have not been well investigated. The influence of hormones on brain development in humans suggests that a positive effect on neurodevelopmental outcome in young boys with XXY may be plausible with hormone replacement therapy. The aim of the study was to investigate retrospectively if an early course of androgen treatment (three injections of testosterone enanthate, 25 mg, each) had an impact on specific domains of neurodevelopmental function in boys with 47,XXY at 36 and 72 months of age. One hundred one boys with a karyotype of 47,XXY had neurodevelopmental assessments. The retrospective chart review resulted in one group (n = 34) who had received androgen treatment during infancy and the second group was untreated (N = 67). Statistical analysis was completed to determine if there was a positive effect from treatment observed at 36 and at 72 months on multiple domains of development. There were significant differences in multiple cognitive domains in the group who received androgen treatment, including multiple measures of language, intellectual, and neuromotor skills. Improved function was observed in neurodevelopmental outcome in boys with 47,XXY at 36 and 72 months who had been treated with a short course of androgen treatment in infancy. Continued research is underway to expand our understanding of the relationship of androgen, brain function, and neurobehavioral and neurodevelopmental outcome in boys with 47,XXY.