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Studying Autism Spectrum Disorder (ASD) heterogeneity in biologically homogeneous samples may increase our knowledge of ASD etiology. Fragile X syndrome (FXS), Angelman syndrome (AS), Tuberous Sclerosis Complex (TSC), and Neurofibromatosis type 1 (NF1) are monogenic disorders with high a prevalence of ASD symptomatology. This study aimed to identify ASD symptom profiles in a large group of children and adolescents (0;9-28 years) with FXS, AS, TSC, and NF1. Data on ASD symptomatology (Autism Diagnostic Observation Scale (ADOS-2) & Social Responsiveness Scale (SRS-2)) were collected from children and adolescents with FXS (n = 54), AS (n = 93), TSC (n = 112), and NF1 (n = 278). To identify groups of individuals with similar ASD profiles, we performed two latent profile analyses. We identified a four-profile model based on the ADOS-2, with a (1) 'Non-spectrum symptom profile', (2) 'Social Affect symptom profile', (3)'Restricted/Repetitive Behaviors symptom profile', and (4)'ASD symptom profile'. We also identified a four-profile model based on the SRS, with a (1)'Non-clinical symptom profile', (2)'Mild symptom profile', (3)'Moderate symptom profile', and (4)'Severe symptom profile'. Although each syndrome group exhibited varying degrees of severity, they also displayed heterogeneity in the profiles in which they were classified. We found distinct ASD symptom profiles in a population consisting of children and adolescents with FXS, AS, TSC, and NF1. Our study highlights the importance of a personalized approach to the identification and management of ASD symptoms in rare genetic syndromes. Future studies should aim to include more domains of functioning and investigate the stability of latent profiles over time., (© 2024. The Author(s).)

Aim: To find proof-of-principle evidence for short-term treatment with lamotrigine to improve cognitive functioning of adolescents with neurofibromatosis type 1 (NF1)., Method: This was a double-blind, parallel-group, randomized, placebo-controlled clinical trial (the NF1-EXCEL trial: Examining the Cognitive and Electrophysiological benefit of Lamotrigine in Neurofibromatosis type 1; Clinicaltrials.gov identifier NCT02256124), with the aim of enrolling 60 adolescents with NF1 aged 12 to 17  years 6 months. The short-term study intervention was 200 mg of lamotrigine taken orally for 26 weeks. The primary outcome was performance IQ tested with the Wechsler Intelligence Scale for Children, Third Edition, complemented with secondary outcomes for visuospatial learning efficacy, visual perception, visual sustained attention, fine motor coordination, attention-deficit/hyperactivity problems, and executive functioning., Results: We screened 402 adolescents with NF1, of whom 31 (eight females) entered the study. Complete-case analysis showed no effect of lamotrigine on either performance IQ (-0.23, 95% CI -6.90 to 6.44) or most secondary outcomes. Visual sustained attention showed a trend towards better performance in the lamotrigine group (-0.81, 95% CI -1.67 to 0.04)., Interpretation: Lamotrigine did not improve cognitive functioning in adolescents with NF1. The small treatment effects make it unlikely that a larger sample size could have changed this conclusion., (© 2024 The Author(s). Developmental Medicine & Child Neurology published by John Wiley & Sons Ltd on behalf of Mac Keith Press.)

Background: Angelman syndrome (AS) is a rare neurodevelopmental disorder characterized by severe intellectual disability, little to no expressive speech, visual and motor problems, emotional/behavioral challenges, and a tendency towards hyperphagia and weight gain. The characteristics of AS make it difficult to measure these children's functioning with standard clinical tests. Feasible outcome measures are needed to measure current functioning and change over time, in clinical practice and clinical trials., Aim: Our first aim is to assess the feasibility of several functional tests. We target domains of neurocognitive functioning and physical growth using the following measurement methods: eye-tracking, functional Near-Infrared Spectroscopy (fNIRS), indirect calorimetry, bio-impedance analysis (BIA), and BOD POD (air-displacement plethysmography). Our second aim is to explore the results of the above measures, in order to better understand the AS phenotype., Methods: The study sample consisted of 28 children with AS aged 2-18 years. We defined an outcome measure as feasible when (1) at least 70% of participants successfully finished the measurement and (2) at least 60% of those participants had acceptable data quality. Adaptations to the test procedure and reasons for early termination were noted. Parents rated acceptability and importance and were invited to make recommendations to increase feasibility. The results of the measures were explored., Results: Outcome measures obtained with eye-tracking and BOD POD met the definition of feasibility, while fNIRS, indirect calorimetry, and BIA did not. The most important reasons for early termination of measurements were showing signs of protest, inability to sit still and poor/no calibration (eye-tracking specific). Post-calibration was often applied to obtain valid eye-tracking results. Parents rated the BOD POD als most acceptable and fNIRS as least acceptable for their child. All outcome measures were rated to be important. Exploratory results indicated longer reaction times to high salient visual stimuli (eye-tracking) as well as high body fat percentage (BOD POD)., Conclusions: Eye-tracking and BOD POD are feasible measurement methods for children with AS. Eye-tracking was successfully used to assess visual orienting functions in the current study and (with some practical adaptations) can potentially be used to assess other outcomes as well. BOD POD was successfully used to examine body composition., Trial Registration: Registered d.d. 23-04-2020 under number 'NL8550' in the Dutch Trial Register: https://onderzoekmetmensen.nl/en/trial/23075., (© 2024. The Author(s).)

Angelman syndrome (AS) is a rare genetic disorder due to lack of UBE3A function on chromosome 15q11.2q13 caused by a deletion, uniparental paternal disomy (UPD), imprinting center disorder (ICD), or pathological variant of the UBE3A gene. AS is characterized by developmental delay, epilepsy, and lack of speech. Although fractures are observed frequently in our clinical practice, there are few studies on bone health in AS. The aim of this study is to investigate bone health in children with AS. In this prospective cohort study, we describe bone health in 91 children with AS visiting the ENCORE Expertise Center for AS between April 2010 and December 2021. Bone health was assessed with the bone health index (BHI) in standard deviation score (SDS) measured by digital radiogrammetry of the left hand using BoneXpert software. Risk factors analyzed were age, sex, genetic subtype, epilepsy, anti-seizure medication use, mobility, body mass index (BMI), and onset of puberty. Children with AS had a mean BHI of -1.77 SDS (SD 1.4). A significantly lower BHI was found in children with a deletion (-2.24 SDS) versus non-deletion (-1.02 SDS). Other factors associated with reduced BHI-SDS were inability to walk and late onset of puberty. Children with a history of one or more fractures (22%) had a significantly lower BHI than children without fractures (-2.60 vs -1.56 SDS). Longitudinal analysis showed a significant decrease in BHI-SDS with age in all genetic subtypes.  Conclusions: Children with AS have a reduced bone health. Risk factors are deletion genotype, no independent walking, and late onset of puberty. Bone health decreased significantly with age. What is Known: • Children with neurological disorders often have a low bone health and higher risk of fractures. • Little is known about bone health in children with Angelman syndrome (AS). What is New: • Children with AS showed a reduced bone health and this was significantly associated with having a deletion, not being able to walk independently, and late onset of puberty. • Longitudinal analysis showed a significant decrease in bone health as children got older., (© 2023. The Author(s).)

Background: The aim of this study was to determine treatment response and whether it is associated with antibody titre change in patients with autoimmune nodopathy (AN) previously diagnosed as chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), and to compare clinical features and treatment response between AN and CIDP., Methods: Serum IgG antibodies to neurofascin-155 (NF155), contactin-1 (CNTN1) and contactin-associated protein 1 (CASPR1) were detected with cell-based assays in patients diagnosed with CIDP. Clinical improvement was determined using the modified Rankin scale, need for alternative and/or additional treatments and assessment of the treating neurologist., Results: We studied 401 patients diagnosed with CIDP and identified 21 patients with AN (10 anti-NF155, 6 anti-CNTN1, 4 anti-CASPR1 and 1 anti-NF155/anti-CASPR1 double positive). In patients with AN ataxia (68% vs 28%, p=0.001), cranial nerve involvement (34% vs 11%, p=0.012) and autonomic symptoms (47% vs 22%, p=0.025) were more frequently reported; patients with AN improved less often after intravenous immunoglobulin treatment (39% vs 80%, p=0.002) and required additional/alternative treatments more frequently (84% vs 34%, p<0.001), compared with patients with CIDP. Antibody titres decreased or became negative in patients improving on treatment. Treatment withdrawal was associated with a titre increase and clinical deterioration in four patients., Conclusions: Distinguishing CIDP from AN is important, as patients with AN need a different treatment approach. Improvement and relapses were associated with changes in antibody titres, supporting the pathogenicity of these antibodies., Competing Interests: Competing interests: MB reports grants from the Dutch Prinses Beatrix Spierfonds (W.OR16-18). LW reports grants from Grifols and the GBS/CIDP Foundation for the study of disease activity biomarkers in CIDP. EE is supported by the Scientific and Technological Research Council of Turkey (TUBITAK) BIDEB-2219 Postdoctoral Research Program. MT was supported by the Erasmus MC Pain Foundation, has received funding from ZonMw (Memorabel programme), the Dutch EpilepsieNL Foundation (NEF 19-08), Dioraphte (2001 0403) and E-RARE JTC 2018 (UltraAIE, 90030376505). PAvD reports grants from Prinses Beatrix Spierfonds, The Netherlands Organisation for Health Research and Development (ZonMW), Sanquin Blood supply, Takeda and Grifols, he is a member of Scientific Advisory Committee/Steering Committee Trials for Annexon, Argenx, Hansa, Octapharma, Sanofi and Roche, all grants and fees were paid to his institution. FE reports grants from ZonMw (Dutch Governmental Agency) and Prinses Beatrix Spierfonds (Dutch Charity Organization) and grants from CSLBehring, Kedrion, Terumo BCT, Grifols and Takeda Pharmaceutical Company, outside the submitted work. Grants were paid to institution and are used for investigator-initiated randomised controlled trials and studies within INCbase, an international CIDP registry. In addition, he received consultancy fee from UCB Pharma, Sanofi and Grifols, paid to institution, outside the submitted work. KK reports grants from Takeda and Grifols (SPIN award). LQ reports grant from Instituto de Salud Carlos III – Ministry of Economy and Innovation (Spain), Fundació La Marató, GBS-CIDP Foundation International, Novartis Pharma Spain, Roche, UCB and Grifols, and received speaker or expert testimony honoraria from CSL Behring, Novartis, Sanofi-Genzyme, Merck, Annexon, Biogen, Janssen, ArgenX, UCB, LFB, Octapharma and Roche, and serves at Clinical Trial Steering Committee for Sanofi Genzyme and Roche, and is Principal Investigator for UCB’s CIDP01 trial. BCJ reports grants for research from Baxalta, Grifols, CSL-Behring, Annexon, Hansa Biopharma, Roche, Prinses Beatrix Spierfonds, GBS-CIDP Foundation International and Horizon 2020, and consultancy fees from Roche and Annexon, and he is chair of the Steering Committee of Internation GBS Outcome Study (IGOS) and member of the Steering Committee of International CIDP Outcome Study (ICOS) and INCbase. RH reports grants from Health~Holland, GBS-CIDP Foundation and Grifols. The ICOS was supported by funding from CSL-Behring and Grifols., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Aim: To identify meaningful outcomes of children and their caregivers attending a paediatric brain centre., Method: We compiled a long list of outcomes of health and functioning of children with brain-related disorders such as cerebral palsy, spina bifida, (genetic) neurodevelopmental disorders, and acquired brain injury. We incorporated three perspectives: patients, health care professionals, and published outcome sets. An aggregated list was categorized using the International Classification of Functioning, Disability, and Health: Children and Youth version in a patient validation survey for children and parent-caregivers to prioritize outcomes. Outcomes were considered meaningful when ranked 'very important' by 70% or more of the participants., Results: We identified 104 outcomes from the three perspectives. After categorizing, 59 outcomes were included in the survey. Thirty-three surveys were completed by children (n = 4), caregivers (n = 24), and parent-caregivers together with their child (n = 5). Respondents prioritized 27 meaningful outcomes covering various aspects of health and functioning: emotional well-being, quality of life, mental and sensory functions, pain, physical health, and activities (communication, mobility, self-care, interpersonal relationships). Parent-caregiver concerns and environmental factors were newly identified outcomes., Interpretation: Children and parent-caregivers identified meaningful outcomes covering various aspects of health and functioning, including caregiver concerns and environmental factors. We propose including those in future outcome sets for children with neurodisability., What This Paper Adds: Outcomes that children with brain-related disorders and their parent-caregivers consider to be the most meaningful cover a wide range of aspects of functioning. Involving these children and their parent-caregivers resulted in the identification of important outcomes that were not covered by professionals and the literature. Parent-caregiver-related factors (coping, burden of care) and environmental factors (support, attitudes, and [health care] services) were identified as meaningful., (© 2023 The Authors. Developmental Medicine & Child Neurology published by John Wiley & Sons Ltd on behalf of Mac Keith Press.)

Angelman Syndrome (AS) is a rare genetic disorder caused by lack of maternal UBE3A protein due to a deletion of the chromosome 15q11.2-q13 region, uniparental paternal disomy, imprinting center defect, or pathogenic variant in the UBE3A gene. Characteristics are developmental delay, epilepsy, behavioral, and sleep problems. There is some evidence for hyperphagia, shorter stature, and higher BMI compared to neurotypical children, but longitudinal studies on growth are lacking. In this study, we analyzed prospectively collected data of 145 children with AS, who visited the ENCORE Expertise Center between 2010 and 2021, with a total of 853 visits. Children showed an elevated mean score of 25 on the Dykens Hyperphagia questionnaire (range 11-55) without genotype association. Higher scores were significantly associated with higher body mass index (BMI) standard deviation scores (SDS) ( p = 0.004). Mean height was -1.2 SDS (SD 1.3), mean BMI-SDS was 0.6 (SD 1.7); 43% had a BMI-SDS > 1 and 20% had a BMI-SDS > 2. Higher BMI-SDS was significantly associated with non-deletion genotype ( p = 0.037) and walking independently ( p = 0.023). Height SDS decreased significantly with age ( p < 0.001) and BMI-SDS increased significantly with age ( p < 0.001. Onset of puberty was normal. In conclusion, children with AS showed moderate hyperphagia, lower height SDS, and higher BMI-SDS compared to norm data, with increasing deviation from the norm with age. It is uncertain how loss of maternal UBE3A function may influence growth. Attention to diet, exercise, and hyperphagia from an early age is recommended to prevent obesity and associated health problems.

Background: Guillain-Barré syndrome (GBS) has a highly variable clinical course and outcome as indicated by the risk of developing respiratory failure and residual inability to walk. Prognostic models as Erasmus GBS Respiratory Insufficiency Score (EGRIS) developed in adult patients are inaccurate in children. Our aim was to determine the prognostic factors of respiratory failure and inability to walk in children with GBS and to develop a new clinical prognostic model for individual patients (EGRIS-Kids)., Methods: A multicenter retrospective cohort study was performed using the data of children (younger than 18 years) fulfilling the diagnostic criteria for GBS from the NINDS. This study was performed in two independent cohorts from centers in Germany, Switzerland, Austria (N = 265, collected 1989-2002) and The Netherlands (N = 156, collected 1987-2016). The predicted main outcomes were occurrence of respiratory failure during the disease course and inability to walk independent at one year after diagnosis., Results: In the combined cohort of 421 children, 79 (19%) required mechanical ventilation and one patient died. The EGRIS-kids was developed including: age, cranial nerve involvement and GBS disability score at admission, resulting in a 9 point score predicting risks of respiratory failure ranging from 4 to 50% (AUC = 0.71). A lower GBS disability score at nadir was the strongest predictor of recovery to independent walking (at one month: OR 0.43 95%CI 0.25-0.74)., Conclusions: EGRIS-Kids and GBS disability score at admission accurately predict the risk of respiratory failure and inability to walk respectively in children with GBS, as tools to personalize the monitoring and treatment., Competing Interests: Declaration of competing interest Drs. J. Roodbol has no disclosures to report. Prof. Dr. R Korinthenberg has no actual conflicts of interest to report. Drs E. Venema has no disclosures to report. Dr. M.C.Y. de Wit received honoraria paid to her institution by Novartis for serving on a steering committee and presenting at a conference, and has received research funding from the Epilepsiefonds (Dutch Epilepsy Foundation), Hersenstichting and Sophia Foundation. Dr. H. F. Lingsma has no disclosures to report. Dr. C.E. Catsman-Berrevoets has no disclosures to report. Dr. B.C. Jacobs has received funding for travel from Baxter International Inc, and has received research funding from the Netherlands Organization for Health Research and Development, Erasmus MC, Prinses Beatrix Spierfonds, Stichting Spieren voor Spieren, CSL-Behring, Grifols, Annexon, Hansa Biopharma and the GBS-CIDP Foundation International., (© 2023 Published by Elsevier Ltd on behalf of European Paediatric Neurology Society.)

Background & Aims: The aim of this study was to investigate the effect of a behavioral intervention on sleep problems, which are significant and an unmet clinical need in children with Angelman Syndrome (AS)., Methods & Procedures: Children (2-18 years) with AS and sleep problems were randomized to a behavioral intervention program or a control group. Intervention consisted of a standardized program including home visits, psycho-education, feedback based on direct observation of bedtime routine and video footage of the night and behavioral treatment techniques by a behavioral therapist. Change in sleep duration (primary) and parental sleep, nighttime visits, sleep hygiene, daytime behavior, parental stress and quality of life (secondary) were assessed post-intervention and at follow-up using questionnaires, diary, actigraphy and videosomnography., Outcomes & Results: The groups, 9 children in each, did not differ at baseline. We found a significant effect of intervention on wake after sleep onset with classical statistical analysis (videosomnography). With single case analysis we found a positive effect on total sleep time (diary and actigraphy) and wake after sleep onset (diary) with a persistent effect on total sleep time (actigraphy) and wake after sleep onset (diary). On secondary outcome there was a significant and persistent effect on sleep hygiene and several quality of life domains., Conclusions & Implications: Behavioral intervention has a positive and persistent effect on sleep problems in children with AS. We advise psycho-education for all parents and use of videosomnography for both evaluation of and feedback on sleep behavior patterns, individual behavioral advice and specific behavioral techniques for children with sleep problems., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Angelman syndrome (AS) is a rare neurogenetic disorder present in approximately 1/12,000 individuals and characterized by developmental delay, cognitive impairment, motor dysfunction, seizures, gastrointestinal concerns, and abnormal electroencephalographic background. AS is caused by absent expression of the paternally imprinted gene UBE3A in the central nervous system. Disparities in the management of AS are a major problem in preparing for precision therapies and occur even in patients with access to experts and recognized clinics. AS patients receive care based on collective provider experience due to limited evidence-based literature. We present a consensus statement and comprehensive literature review that proposes a standard of care practices for the management of AS at a critical time when therapeutics to alter the natural history of the disease are on the horizon., Methods: We compiled the key recognized clinical features of AS based on consensus from a team of specialists managing patients with AS. Working groups were established to address each focus area with committees comprised of providers who manage >5 individuals. Committees developed management guidelines for their area of expertise. These were compiled into a final document to provide a framework for standardizing management. Evidence from the medical literature was also comprehensively reviewed., Results: Areas covered by working groups in the consensus document include genetics, developmental medicine, psychology, general health concerns, neurology (including movement disorders), sleep, psychiatry, orthopedics, ophthalmology, communication, early intervention and therapies, and caregiver health. Working groups created frameworks, including flowcharts and tables, to help with quick access for providers. Data from the literature were incorporated to ensure providers had review of experiential versus evidence-based care guidelines., Conclusion: Standards of care in the management of AS are keys to ensure optimal care at a critical time when new disease-modifying therapies are emerging. This document is a framework for providers of all familiarity levels., (© 2021 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals LLC.)

Background: Disordered thyroid hormone transport, due to mutations in the SLC16A2 gene encoding monocarboxylate transporter 8 (MCT8), is characterised by intellectual and motor disability resulting from cerebral hypothyroidism and chronic peripheral thyrotoxicosis. We sought to systematically assess the phenotypic characteristics and natural history of patients with MCT8 deficiency., Methods: We did an international, multicentre, cohort study, analysing retrospective data from Jan 1, 2003, to Dec 31, 2019, from patients with MCT8 deficiency followed up in 47 hospitals in 22 countries globally. The key inclusion criterion was genetically confirmed MCT8 deficiency. There were no exclusion criteria. Our primary objective was to analyse the overall survival of patients with MCT8 deficiency and document causes of death. We also compared survival between patients who did or did not attain full head control by age 1·5 years and between patients who were or were not underweight by age 1-3 years (defined as a bodyweight-for-age Z score <-2 SDs or <5th percentile according to WHO definition). Other objectives were to assess neurocognitive function and outcomes, and clinical parameters including anthropometric characteristics, biochemical markers, and neuroimaging findings., Findings: Between Oct 14, 2014, and Jan 17, 2020, we enrolled 151 patients with 73 different MCT8 (SLC16A2) mutations. Median age at diagnosis was 24·0 months (IQR 12·0-60·0, range 0·0-744·0). 32 (21%) of 151 patients died; the main causes of mortality in these patients were pulmonary infection (six [19%]) and sudden death (six [19%]). Median overall survival was 35·0 years (95% CI 8·3-61·7). Individuals who did not attain head control by age 1·5 years had an increased risk of death compared with patients who did attain head control (hazard ratio [HR] 3·46, 95% CI 1·76-8·34; log-rank test p=0·0041). Patients who were underweight during age 1-3 years had an increased risk for death compared with patients who were of normal bodyweight at this age (HR 4·71, 95% CI 1·26-17·58, p=0·021). The few motor and cognitive abilities of patients did not improve with age, as evidenced by the absence of significant correlations between biological age and scores on the Gross Motor Function Measure-88 and Bayley Scales of Infant Development III. Tri-iodothyronine concentrations were above the age-specific upper limit in 96 (95%) of 101 patients and free thyroxine concentrations were below the age-specific lower limit in 94 (89%) of 106 patients. 59 (71%) of 83 patients were underweight. 25 (53%) of 47 patients had elevated systolic blood pressure above the 90th percentile, 34 (76%) of 45 patients had premature atrial contractions, and 20 (31%) of 64 had resting tachycardia. The most consistent MRI finding was a global delay in myelination, which occurred in 13 (100%) of 13 patients., Interpretation: Our description of characteristics of MCT8 deficiency in a large patient cohort reveals poor survival with a high prevalence of treatable underlying risk factors, and provides knowledge that might inform clinical management and future evaluation of therapies., Funding: Netherlands Organisation for Health Research and Development, and the Sherman Foundation., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

DNA double-strand breaks (DSBs) are highly toxic DNA lesions that can lead to chromosomal instability, loss of genes and cancer. The MRE11/RAD50/NBN (MRN) complex is keystone involved in signaling processes inducing the repair of DSB by, for example, in activating pathways leading to homologous recombination repair and nonhomologous end joining. Additionally, the MRN complex also plays an important role in the maintenance of telomeres and can act as a stabilizer at replication forks. Mutations in NBN and MRE11 are associated with Nijmegen breakage syndrome (NBS) and ataxia telangiectasia (AT)-like disorder, respectively. So far, only one single patient with biallelic loss of function variants in RAD50 has been reported presenting with features classified as NBS-like disorder. Here, we report a long-term follow-up of an unrelated patient with facial dysmorphisms, microcephaly, skeletal features, and short stature who is homozygous for a novel variant in RAD50. We could show that this variant, c.2524G > A in exon 15 of the RAD50 gene, induces aberrant splicing of RAD50 mRNA mainly leading to premature protein truncation and thereby, most likely, to loss of RAD50 function. Using patient-derived primary fibroblasts, we could show abnormal radioresistant DNA synthesis confirming pathogenicity of the identified variant. Immunoblotting experiments showed strongly reduced protein levels of RAD50 in the patient-derived fibroblasts and provided evidence for a markedly reduced radiation-induced AT-mutated signaling. Comparison with the previously reported case and with patients presenting with NBS confirms that RAD50 mutations lead to a similar, but distinctive phenotype., (© 2020 The Authors. American Journal of Medical Genetics Part A published by Wiley Periodicals, Inc.)

This study presents a broad overview of health issues and psychomotor development of 100 children with Angelman syndrome (AS), seen at the ENCORE Expertise Center for AS in Rotterdam, the Netherlands. We aimed to further delineate the phenotype of AS, to evaluate the association of the phenotype with genotype and other determinants such as epilepsy and to get insight in possible targets for intervention. We confirmed the presence of a more severe phenotype in the 15q11.2-q13 deletion subtype. Novel findings were an association of (early onset of) epilepsy with a negative effect on development, a high occurrence of nonconvulsive status epilepticus, a high rate of crouch gait in the older children with risk of deterioration of mobility, a relatively low occurrence of microcephaly, a higher mean weight for height in all genetic subtypes with a significant higher mean in the nondeletion children, and a high occurrence of hyperphagia across all genetic subtypes. Natural history data are needed to design future trials. With this large clinical cohort with structured prospective and multidisciplinary follow-up, we provide unbiased data on AS to support further intervention studies to optimize outcome and quality of life of children with AS and their family., (© 2019 The Authors. American Journal of Medical Genetics Part A published by Wiley Periodicals, Inc.)

Objective: To investigate whether mammalian target of rapamycin inhibitor everolimus can improve intellectual disability, autism, and other neuropsychological deficits in children with tuberous sclerosis complex (TSC)., Methods: In this 12-month, randomized, double-blind, placebo-controlled trial, we attempted to enroll 60 children with TSC and IQ <80, learning disability, special schooling, or autism, aged 4-17 years, without intractable seizures to be assigned to receive everolimus or placebo. Everolimus was titrated to blood trough levels of 5-10 ng/mL. Primary outcome was full-scale IQ; secondary outcomes included autism, neuropsychological functioning, and behavioral problems., Results: Thirty-two children with TSC were randomized. Intention-to-treat analysis showed no benefit of everolimus on full-scale IQ (treatment effect -5.6 IQ points, 95% confidence interval -12.3 to 1.0). No effect was found on secondary outcomes, including autism and neuropsychological functioning, and questionnaires examining behavioral problems, social functioning, communication skills, executive functioning, sleep, quality of life, and sensory processing. All patients had adverse events. Two patients on everolimus and 2 patients on placebo discontinued treatment due to adverse events., Conclusions: Everolimus did not improve cognitive functioning, autism, or neuropsychological deficits in children with TSC. The use of everolimus in children with TSC with the aim of improving cognitive function and behavior should not be encouraged in this age group., Clinicaltrialsgov Identifier: NCT01730209., Classification of Evidence: This study provides Class I evidence that for children with TSC, everolimus does not improve intellectual disability, autism, behavioral problems, or other neuropsychological deficits., (© 2019 American Academy of Neurology.)

Background: Computed tomography (CT), a strong diagnostic tool, delivers higher radiation doses than most imaging modalities. As CT use has increased rapidly, radiation protection is important, particularly among children. We evaluate leukemia and brain tumor risk following exposure to low-dose ionizing radiation from CT scans in childhood., Methods: For a nationwide retrospective cohort of 168 394 children who received one or more CT scans in a Dutch hospital between 1979 and 2012 who were younger than age 18 years, we obtained cancer incidence, vital status, and confounder information by record linkage with external registries. Standardized incidence ratios were calculated using cancer incidence rates from the general Dutch population. Excess relative risks (ERRs) per 100 mGy organ dose were calculated with Poisson regression. All statistical tests were two-sided., Results: Standardized incidence ratios were elevated for all cancer sites. Mean cumulative bone marrow doses were 9.5 mGy at the end of follow-up, and leukemia risk (excluding myelodysplastic syndrome) was not associated with cumulative bone marrow dose (44 cases). Cumulative brain dose was on average 38.5 mGy and was statistically significantly associated with risk for malignant and nonmalignant brain tumors combined (ERR/100 mGy: 0.86, 95% confidence interval = 0.20 to 2.22, P = .002, 84 cases). Excluding tuberous sclerosis complex patients did not substantially change the risk., Conclusions: We found evidence that CT-related radiation exposure increases brain tumor risk. No association was observed for leukemia. Compared with the general population, incidence of brain tumors was higher in the cohort of children with CT scans, requiring cautious interpretation of the findings., (© The Author(s) 2018. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Tuberous Sclerosis Complex (TSC) is characterized by a high prevalence of autism spectrum disorders (ASD). Little is known about the relation between cortical dysplasia and ASD severity in TSC. We assessed ASD severity (using the Autism Diagnostic Observation Scale), tuber and radial migration line (RML) count and location, and cognitive functioning in 52 children with TSC and performed regression and mediation analyses. Tuber and RML count were strongly positively related to ASD severity. However, when correcting for cognitive functioning, the majority of associations became insignificant and only total tuber count remained associated to the severity of restricted/repetitive behaviors. Occipital RML count remained associated with overall ASD severity, and social communication/interaction deficit severity specifically. This study shows the important explanatory role of cognitive functioning in the association between cortical dysplasia and ASD severity, and the relevance of separately studying the two ASD subdomains.

Residual motor nerve dysfunction after pediatric Guillain-Barré syndrome (GBS) was determined in an observational cross-sectional cohort study in patients who previously developed GBS during childhood (<18 years). Ulnar motor nerve dysfunction was defined by compound motor action potential (CMAP) scan in patients after a follow up of at least 1 year compared with age-matched healthy controls, in relation to clinical course and outcome. A total of 37 persons previously diagnosed with GBS in childhood were included with a mean age at current examination of 20.6 years (4-39 years). The median time between diagnosis and follow-up was 11 years (range: 1-22 years). CMAP scanning indicated ulnar motor nerve dysfunction in 25 (68%) participants. The most frequent abnormality was a reduction in nerve excitability observed both in those with residual limb weakness and in the majority of those with complete recovery. CMAP scan characteristics were not related to prognostic factors or outcome. In conclusion, GBS in childhood results in residual motor nerve excitability disturbances, even in those completely recovered, probably reflecting altered physiology of regenerated peripheral nerves., (© 2017 Peripheral Nerve Society.)

To describe the key diagnostic features of pediatric Guillain-Barré syndrome (GBS) and validate the Brighton criteria. Retrospective cohort study of all children (<18 years) diagnosed with GBS between 1987 and 2013 at Sophia Children's Hospital, Erasmus MC, Rotterdam. Clinical information was collected and the sensitivity of the Brighton criteria was calculated. 67 children (35 boys) were included, with a median age of 5.0 years [interquartile range (IQR) 3.0-10.0 years]. Bilateral limb weakness was present at hospital admission in 93% of children, and at nadir in all patients. Children presented with tetraparesis in 70% or with paraparesis in 23%. Reduced reflexes in paretic limbs were observed at hospital admission in 82% and during follow-up in all children. The progressive phase lasted median 6 days (IQR 3-8 days) and less than 4 weeks in all children. A monophasic disease course was seen in 97%, including 5 children with a treatment-related fluctuation. Two children had a later relapse at 9 weeks and 19 weeks after onset. 77% of the children showed an elevated protein level in CSF. Nerve conduction studies showed evidence for a poly(radiculo)neuropathy in 91% of the children. 46 children had a complete data set, the sensitivity of the Brighton criteria level 1 was 72% (95% CI 57-84) and 96% (95% CI 85-99) for level 2 and 98% (95% CI 88-100) for level 3. The majority of the pediatric GBS patients presented in this cohort fulfilled the current diagnostic criteria.

Structural brain malformations associated with Tuberous Sclerosis Complex (TSC) are related to the severity of the clinical symptoms and can be visualized by magnetic resonance imaging (MRI). Tuberous Sclerosis Complex is caused by inactivating TSC1 or TSC2 mutations. We investigated associations between TSC brain pathology and different inactivating TSC1 and TSC2 variants, and examined the potential prognostic value of subdivision of TSC2 variants based on their predicted effects on TSC2 expression. We performed genotype-phenotype associations of TSC-related brain pathology on a cohort of 64 children aged 1.4-17.9 years. Brain abnormalities were assessed using MRI. Individuals were grouped into those with an inactivating TSC1 variant and those with an inactivating TSC2 variant. The TSC2 group was subdivided into changes predicted to result in TSC2 protein expression (TSC2p) and changes predicted to prevent expression (TSC2x). The TSC2 group was associated with more and larger tubers, more radial migration lines, and more subependymal nodules than the TSC1 group. Subependymal nodules were also more likely to be calcified. Subdivision of the TSC2 group did not reveal additional, substantial differences, except for a larger number of tubers in the temporal lobe and a larger fraction of cystic tubers in the TSC2x subgroup. The severity of TSC-related brain pathology was related to the presence of an inactivating TSC2 variant. Although larger studies might find specific TSC2 variants that have prognostic value, in our cohort, subdivision of the TSC2 group did not lead to better prediction., Competing Interests: R Swenker reports financial assistance from Novartis. MCY de Wit reports grants from Dutch Epilepsy Foundation, and grants and non-financial support from Novartis outside the submitted work; and the Erasmus MC received honoraria from Novartis for educational lectures presented by the author. The remaining authors declare no conflict of interest.

Recent advances in treatment have achieved a large drop in the prevalence of active leprosy cases, but the incidence is at best decreasing slowly. Most people within leprosy-endemic populations have been exposed to Mycobacterium leprae, but few develop disease and it seems likely that the majority of the population develops protective immunity. If the site of initial infection is in the nose, dissemination of bacilli around the body to skin and nerve implies that the initial infection is bacilliferous and it has been shown that nasal M. leprae are detectable by polymerase chain reaction (PCR) of nasal swabs. Since salivary anti-M. leprae IgA (sMLIgA) levels are correlated with protection, we have surveyed groups of leprosy patients, contacts and the general population for both their sMLIgA and nasal PCR positivity. A total of 304 subjects were enrolled in the study: PCR and mucosal challenge tests were performed in 204 of these individuals. sMLIgA was present in 66% of treated patients, 76% of leprosy workers and 72% of healthy contacts. However, only 33% of indigenous subjects were sMLIgA+, in contrast to the earlier studies showing 74% positivity. PCR for M. leprae was present in both household contacts (2%) and indigenous controls (5%). In a subsequent follow-up study, nasal swabs were taken from 97 of those studied in the first series: three PCR+ individuals followed up after one year became negative, while of the remaining 94 PCR- individuals retested, 2 became positive. Of 112 subjects retested with the mucosal challenge test for sMLIgA: 22 converted from positive to negative and 12 from negative to positive. These results suggest that there is widespread subclinical transmission of M. leprae with transient infection of the nose resulting in the development of a mucosal immune response, despite the fact that few individuals will develop clinical disease. This may explain the current lack of effect of multidrug therapy (MDT) control programmes on incidence, although the reduction in general population immunity is consistent with some effect of MDT on transmission.

Previous studies have found Mycobacterium leprae in nasal swabs from leprosy patients, their contacts, and persons living in endemic areas. It might be expected that M. tuberculosis would be present on nasal mucosa of pulmonary tuberculosis patients, but whether they can be detected in patients or contacts is unknown. We used the polymerase chain reaction (PCR) technique on nasal swabs from tuberculosis patients, contacts of tuberculosis patients, leprosy patients, and London controls to look for both M. tuberculosis and M. leprae. Swabs dipped in sputum specimens from smear-positive patients were used as positive controls. The PCRs were conducted in two independent laboratories. M. tuberculosis was detected in nasal swabs from 6/16 smear-positive tuberculosis patients and from 1/10 household contacts by one of the laboratories. All of the sputum swabs were positive for M. tuberculosis, and all of the London controls were negative. M. leprae were found in nasal swabs from 2/5 leprosy patients, but one laboratory also reported M. leprae in swabs from 4/21 tuberculosis patients and from one sputum specimen. The results show that M. tuberculosis can be found in the noses of some tuberculosis patients, and suggest that the bacilli also may be detected in some household contacts. The comparisons with M. leprae and between the two laboratories give further insights into the sensitivity and specificity of the technique.

Leprosy is still a health problem in many countries. Because the causative organism, Mycobacterium leprae cannot be cultured in vitro, it is virtually impossible to assess exposure, and the onset of infection and disease. As a consequence, the chain of infection, considered as the relationships between M. leprae, transmission and human host, is poorly understood. Here, we discuss a number of organism-, host- and environmental-related factors which may be incriminated in the dynamic process of the development of leprosy disease. The use of modern molecular and immunological tools has become a valuable addition to epidemiological research. Understanding of the epidemiology of leprosy is a prerequisite for effective control of the disease.

In order to understand better the relationship among Mycobacterium leprae, its transmission and the human host or the chain of infection which may lead to the development of leprosy, we performed a population survey in which nasal carriage of M. leprae was determined by a specific polymerase chain reaction (PCR), 2 years after an earlier survey in the same population. 1923 persons were registered, 1171 were clinically examined for signs of leprosy, and 418 were tested by PCR. The detection rate of leprosy in the study area had not changed significantly during the 2 years' observation period since the introduction of multi-drug therapy, i.e. 6/1000 compared to 7.7/1000 2 years before. Of 6 newly detected cases, 5 were diagnosed as having paucibacillary leprosy. The presence of M. leprae could be demonstrated by PCR in 2.9% (12/418) of the persons. PCR positivity was not persistent over the 2 years. All the PCR positive persons identified in the first survey were negative in the second, indicating that M. leprae nasal carriage is transient. As in the previous survey, we found evidence for widespread M. leprae nasal carriage as determined by PCR among the general population in an area in which leprosy is endemic. In addition, our data indicated that PCR positivity can occur in certain clusters in the community. This clustering seems to be time-dependent, not necessarily related to the presence of patients.

To test for genotypic variations between different isolates of Mycobacterium leprae, the causative agent of leprosy, the 282 bp spacer region between the 16S and 23S rRNA genes was amplified using PCR, and submitted to single-strand conformation polymorphism (SSCP) analysis. The procedure was optimized using four modified spacer fragments, containing mutations at one, three, four and six positions, respectively. Seventy-five M. leprae isolates from different sources, including isolates from leprosy patients, healthy individuals, armadillos and mouse footpads were identical in the SSCP analysis. DNA sequencing and restriction enzyme analysis performed on four and 40 samples, respectively, confirmed the results obtained with SSCP analysis.

In order to better understand the role of Mycobacterium leprae nasal carriage in the maintenance of infection reservoirs and transmission of leprosy, we applied a polymerase chain reaction (PCR) that detected a 531-bp fragment of the pra gene of M. leprae on nasal swab specimens collected through a total population survey from individuals living in an area in which leprosy is endemic. Among the total tested population of 1,228 people, 7.8% were found to be PCR positive. PCR positivity was shown to be randomly distributed among the population for which leprosy is endemic. No association was observed between PCR positivity, age, or sex. The observed distribution of PCR positivity among households of different sizes confirmed the expected values, with the exception of two households, each with three people with PCR-positive nasal swab specimens. Although nasal carriage does not necessarily imply infection or excretion of bacilli, the finding of nasal carriage supports the theory of a disseminated occurrence of M. leprae in populations for which leprosy is endemic.

The polymerase chain reaction based on the selective amplification of a 531-bp fragment of the gene encoding the proline-rich antigen of Mycobacterium leprae was applied to nasal swab specimens from leprosy patients, occupational contacts, and endemic and nonendemic controls. To prevent false-positive amplification, we used dUTP and uracil-DNA-glycosylase in all polymerase chain reactions. False-negative reactions were detected by using a 531-bp modified template as an internal control. Amplification products were found in 55% of untreated patients, in 19% of the occupational contacts, in 12% of endemic controls, and in none of the nonendemic controls. This study strongly suggests that not only leprosy patients but also healthy persons may carry M. leprae. We concluded that polymerase chain reaction is a reliable method to detect M. leprae in nasal specimens. The method holds promise for studying the spread and transmission of M. leprae within a population.

A colorimetric assay for the detection of PCR-products is described. The assay is based on amplification of DNA in the presence of digoxigenin-dUTP. After immobilization of the PCR products to a microtitre plate, amplified DNA could be detected colorimetrically. The sensitivity of this colorimetric assay was equal to gel-analysis allowing the detection of 100 fg of template DNA. Here, we show that it can be used to detect Mycobacterium leprae DNA in biopsy specimens from leprosy patients. The simplicity and the low degree of variation make this assay an alternative to gel-analysis.

The polymerase chain reaction (PCR) based on the selective amplification of a 530-bp fragment of the gene encoding the proline-rich antigen of Mycobacterium leprae was applied on sections of fixed or frozen biopsy samples from leprosy patients. A simple procedure for the extraction of DNA from M. leprae in clinical specimens that provided suitable template DNA for amplification was developed. When PCR was applied on frozen sections, positive amplification in samples from all untreated acid-fast bacillus (AFB)-positive patients and in samples from 56% of the untreated AFB-negative patients could be detected, while biopsy samples from patients with skin diseases other than leprosy were all PCR negative. With neutral Formalin-fixed biopsy samples, positive amplification in 92% of the samples from untreated AFB-positive patients and in 61% of the samples from untreated AFB-negative patients could be detected by PCR. Biopsy samples exposed to mercuric chloride or nonbuffered formaldehyde containing fixatives were not suitable for application of PCR. This PCR holds promise as a tool for studies on M. leprae infection.

Using synthetic peptides representing overlapping sequences of the 100-amino-acid-long N-terminal region of the proline-rich antigen of Mycobacterium leprae (PRA), we have mapped the epitopes in the primary structure of PRA recognized by four monoclonal antibodies. The M. leprae-specific monoclonal antibody F47-9 recognized the amino acid sequence LGSAYP (residues 34 to 39). Both monoclonal antibodies F67-1 and F67-5 recognized the sequence YPPP within the repeated sequence of PRA at four sites (residues 38 to 41, 50 to 53, 60 to 63, and 70 to 73). Monoclonal antibody F126-5 recognized the sequence SYPPP, also within the repeat, at three sites (residues 49 to 53, 59 to 63, and 69 to 73). All three epitopes appeared to be linear as far as can be determined by this approach.

A Mycobacterium leprae expression library was constructed in the vectors EX1, pEX2, and pEX3 and screened with a pool of 19 well-absorbed sera from household contacts of leprosy patients. Twelve selected recombinants that were further characterized differed clearly from recombinants selected with murine monoclonal antibodies. Whereas the monoclonal antibodies recognized mainly six recombinant antigens, the human sera from contacts reacted with a range of different recombinant antigens. None of the contact recombinant antigens was identical or related to well-characterized antigens from M. leprae or other mycobacteria selected with monoclonal antibodies, including proteins of the heat shock families. Two groups of recombinant antigens could be distinguished: one that was recognized by all sera used in the pool and one that was recognized by only a limited number of sera. These antigens, selected with sera from household contacts of previously untreated lepromatous leprosy patients, may be relevant to the immune responses during the early phase of infection with M. leprae.

The 36,000-molecular-weight antigen (36K antigen) of Mycobacterium leprae is a major immunogenic protein carrying common and specific antigenic determinants recognized by antibodies and T cells in leprosy patients. Recombinant DNA clones containing the complete gene coding for the 36 K antigen, designated in this paper as PRA, were isolated from both lambda gt11 and cosmid libraries of the M. leprae genome. The DNA sequence of the pra gene coded for a polypeptide of 249 amino acids with a predicted molecular mass of 26,299 daltons. The deduced amino acid sequence revealed a proline-rich (42%) amino-terminal region containing a number of repeated sequences similar or identical to the sequence PGGSYPPPPP. The reactivity of four monoclonal antibodies (F47-9, F67-1, F67-5, and F126-5) was directed to this proline-rich region of the PRA protein. DNA sequence and immunological data indicated that the lambda gt11 recombinant Y3180, which was previously isolated by using antibody F47-9 (R. A. Young, V. Mehra, D. Sweetser, T. Buchanan, J. Clark-Curtiss, R. W. Davis, and B. R. Bloom, Nature (London) 316:450-452, 1985), specifies a fusion protein unrelated to PRA but containing a similar epitope recognized by F47-9.

Leprosy displays a remarkable spectrum of symptoms correlating with the T-cell-mediated immune reactivity of the host against the causative organism, Mycobacterium leprae. At one pole of this spectrum are lepromatous leprosy patients showing a M. leprae-specific T-cell unresponsiveness; at the other are tuberculoid leprosy patients displaying both acquired immunity and delayed-type hypersensitivity against M. leprae which are thought to be conferred by helper T (Th) cells. Because well-defined M. leprae antigens are crucial for the prevention and control of leprosy, we have cloned M. leprae-reactive T cells (TLC) of the helper phenotype from a tuberculoid leprosy patient. As reported here, these TLC show an unexpected diversity in the recognition of M. leprae and related mycobacteria, which is different from that exhibited by monoclonal antibodies. Half of these TLC are completely or almost M. leprae-specific, whereas the other half are cross-reactive with most or all other mycobacteria. A M. leprae protein of relative molecular mass (Mr) 36,000 (36K) defined by a M. leprae-specific monoclonal antibody stimulates 4 out of 6 TLC tested. Each of these TLC recognizes a different antigenic determinant, one of which is M. leprae-specific. The previous paper describes other M. leprae-specific T-cell clones half of which recognize an epitope on a M. leprae protein of Mr 18 K.

Thirty-one dapsone resistant lepromatous leprosy patients receiving clofazimine based therapy were serologically monitored throughout their 5-year period of treatment. Sequentially collected sera were used to examine 4 Mycobacterium leprae antigens to evaluate their usefulness in ELISA's for monitoring the progress of their therapy. The ELISA results were compared with decline in bacterial load over the treatment period and with duration of treatment. In addition the ELISA's were compared with each other. The ELISA's based on the measurement of IgM antibodies to the two neoglycoproteins (NDO and NTO) representing the phenolic glycolipid antigen of M. leprae were found to be the most effective with regard to monitoring treatment. A whole M. leprae based ELISA was less efficient in monitoring treatment because it failed to measure antibodies in 5 out of 31 patients. The ELISA-inhibition test based on the detection of antibodies to a species-specific epitope on the 36 K antigen of M. leprae was less suitable because of persistent reactivity during therapy.

A polymerase chain reaction (PCR) using heat-stable Taq polymerase is described for the specific detection of Mycobacterium leprae, the causative agent of leprosy. A set of primers was selected on the basis of the nucleotide sequence of a gene encoding the 36 kDa antigen of M. leprae. With this set of primers in the PCR, M. leprae could be detected specifically with a detection limit approximating one bacterium. This PCR appears to meet the criteria of specificity and sensitivity required for a useful tool in epidemiology and eventually for the control of leprosy.

In this study a mouse monoclonal antibody (47-9) is described, which recognized an epitope on the 36 kD protein antigen of M. leprae. The monoclonal antibody showed specificity for M. leprae. An ELISA-inhibition test based on the competitive inhibition by antibodies from human test sera of the binding of the enzyme labelled monoclonal antibody to M. leprae was developed. Seropositivity was found in 100% of the multibacillary leprosy patients group and in 91% of the paucibacillary patients. Only 5% of the 223 control sera were positive. Because of the high seropositivity found in both multi- and paucibacillary patients, it is suggested that the epitope on the 36 kD antigen is immuno-dominant. Therefore the ELISA-inhibition test described herein might well be a suitable tool for diagnosis of leprosy.

A 36 kDa antigen of Mycobacterium leprae was purified by phenol biphasic partition followed by preparative SDS-PAGE. The purified antigen appeared as a single band in SDS-PAGE and eluted as a single peak in ion-exchange chromatography. The antigen comprised epitopes which were cross-reactive with M. tuberculosis, as well as a species-specific epitope (recognized by MAb F47-9). Different treatments of the 36 kDa antigen suggested it to be largely protein in nature; the amino acid composition of 81% of the antigen was determined. A majority of sera from leprosy patients contained antibodies recognizing the 36 kDa antigen.

Thirty-five previously untreated lepromatous patients receiving dapsone-based therapy were monitored throughout their 5-year period of treatment by serology and by pathology. Sequentially collected sera were used to evaluate the usefulness of four Mycobacterium leprae antigens as used in ELISA to monitor the progress of their therapy. ELISA results were compared with each other and with bacterial load over the treatment period and with duration of treatment. The ELISAs, based on the measurement of IgM antibody reactivity to the two neoglycoproteins (NDO and NTO) representing the phenolic glycolipid antigen of M. leprae, were found to be the most effective in monitoring treatment. A whole M. leprae based ELISA was less efficient in monitoring treatment because it failed to measure antibodies in 8 out of 35 patients and because it provided consistently lower values than either NTO or NDO. The ELISA-inhibition test based on the detection of antibodies to a species-specific epitope on the 36 K antigen of M. leprae was less suitable because of persistent reactivity during therapy, consequently resulting in no significant correlation with ELISA reactivities to NTO or NDO.