Pitt-Hopkins syndrome (PTHS) is a rare, genetic disorder caused by a molecular variant of TCF4 which is involved in embryologic neuronal differentiation. PTHS is characterized by syndromic facies, psychomotor delay, and intellectual disability. Other associated features include early-onset myopia, seizures, constipation, and hyperventilation-apneic spells. Many also meet criteria for autism spectrum disorder. Here the authors present a series of 23 PTHS patients with molecularly confirmed TCF4 variants and describe 3 unique individuals. The first carries a small deletion but does not exhibit the typical facial features nor the typical pattern of developmental delay. The second exhibits typical facial features, but has attained more advanced motor and verbal skills than other reported cases to date. The third displays typical features of PTHS, however inherited a large chromosomal duplication involving TCF4 from his unaffected father with somatic mosaicism. To the authors' knowledge, this is the first chromosomal duplication case reported to date.

Variants in CLCN4, which encodes the chloride/hydrogen ion exchanger CIC-4 prominently expressed in brain, were recently described to cause X-linked intellectual disability and epilepsy. We present detailed phenotypic information on 52 individuals from 16 families with CLCN4-related disorder: 5 affected females and 2 affected males with a de novo variant in CLCN4 (6 individuals previously unreported) and 27 affected males, 3 affected females and 15 asymptomatic female carriers from 9 families with inherited CLCN4 variants (4 families previously unreported). Intellectual disability ranged from borderline to profound. Behavioral and psychiatric disorders were common in both child- and adulthood, and included autistic features, mood disorders, obsessive–compulsive behaviors and hetero- and autoaggression. Epilepsy was common, with severity ranging from epileptic encephalopathy to well-controlled seizures. Several affected individuals showed white matter changes on cerebral neuroimaging and progressive neurological symptoms, including movement disorders and spasticity. Heterozygous females can be as severely affected as males. The variability of symptoms in females is not correlated with the X inactivation pattern studied in their blood. The mutation spectrum includes frameshift, missense and splice site variants and one single-exon deletion. All missense variants were predicted to affect CLCN4’s function based on in silico tools and either segregated with the phenotype in the family or were de novo. Pathogenicity of all previously unreported missense variants was further supported by electrophysiological studies in Xenopus laevis oocytes. We compare CLCN4-related disorder with conditions related to dysfunction of other members of the CLC family.

† The COVID19 pandemic is causing an unprecedented public health crisis impacting healthcare systems, healthcare workers and communities. The COVID-19 Pandemic Health System REsilience PROGRAM (REPROGRAM) consortium is an international not-for-profit think-tank established to champion the safety of healthcare workers, policy development and advocacy for global pandemic preparedness and action Specialty section: This article was submitted to Dementia and Neurodegenerative Diseases, a section of the journal Frontiers in Neurology

BackgroundExon-targeted microarrays can detect small (<1000 bp) intragenic copy number variants (CNVs), including those that affect only a single exon. This genome-wide high-sensitivity approach increases the molecular diagnosis for conditions with known disease-associated genes, enables better genotype–phenotype correlations, and facilitates variant allele detection allowing novel disease gene discovery.MethodsWe retrospectively analyzed data from 63,127 patients referred for clinical chromosomal microarray analysis (CMA) at Baylor Genetics laboratories, including 46,755 individuals tested using exon-targeted arrays, from 2007 to 2017. Small CNVs harboring a single gene or two to five non-disease-associated genes were identified; the genes involved were evaluated for a potential disease association.ResultsIn this clinical population, among rare CNVs involving any single gene reported in 7200 patients (11%), we identified 145 de novo autosomal CNVs (117 losses and 28 intragenic gains), 257 X-linked deletion CNVs in males, and 1049 inherited autosomal CNVs (878 losses and 171 intragenic gains); 111 known disease genes were potentially disrupted by de novo autosomal or X-linked (in males) single-gene CNVs. Ninety-one genes, either recently proposed as candidate disease genes or not yet associated with diseases, were disrupted by 147 single-gene CNVs, including 37 de novo deletions and ten de novo intragenic duplications on autosomes and 100 X-linked CNVs in males. Clinical features in individuals with de novo or X-linked CNVs encompassing at most five genes (224 bp to 1.6 Mb in size) were compared to those in individuals with larger-sized deletions (up to 5 Mb in size) in the internal CMA database or loss-of-function single nucleotide variants (SNVs) detected by clinical or research whole-exome sequencing (WES). This enabled the identification of recently published genes (BPTF, NONO, PSMD12, TANGO2, and TRIP12), novel candidate disease genes (ARGLU1 and STK3), and further confirmation of disease association for two recently proposed disease genes (MEIS2 and PTCHD1). Notably, exon-targeted CMA detected several pathogenic single-exon CNVs missed by clinical WES analyses.ConclusionsTogether, these data document the efficacy of exon-targeted CMA for detection of genic and exonic CNVs, complementing and extending WES in clinical diagnostics, and the potential for discovery of novel disease genes by genome-wide assay.Electronic supplementary materialThe online version of this article (doi:10.1186/s13073-017-0472-7) contains supplementary material, which is available to authorized users.

Point mutations and genomic deletions of the CDKL5 (STK9) gene on chromosome Xp22 have been reported in patients with severe neurodevelopmental abnormalities, including Rett-like disorders. To date, only larger-sized (8-21 Mb) duplications harboring CDKL5 have been described. We report seven females and four males from seven unrelated families with CDKL5 duplications 540-935 kb in size. Three families of different ethnicities had identical 667 kb duplications containing only the shorter CDKL5 isoform. Four affected boys, 8-14 years of age, and three affected girls, 6-8 years of age, manifested autistic behavior, developmental delay, language impairment, and hyperactivity. Of note, two boys and one girl had macrocephaly. Two carrier mothers of the affected boys reported a history of problems with learning and mathematics while at school. None of the patients had epilepsy. Similarly to CDKL5 mutations and deletions, the X-inactivation pattern in all six studied females was random. We hypothesize that the increased dosage of CDKL5 might have affected interactions of this kinase with its substrates, leading to perturbation of synaptic plasticity and learning, and resulting in autistic behavior, developmental and speech delay, hyperactivity, and macrocephaly.

Autism spectrum disorder (ASD) can be reliably diagnosed at 18 months, yet significant diagnostic delays persist in the United States. This double-blinded, multi-site, prospective, active comparator cohort study tested the accuracy of an artificial intelligence-based Software as a Medical Device designed to aid primary care healthcare providers (HCPs) in diagnosing ASD. The Device combines behavioral features from three distinct inputs (a caregiver questionnaire, analysis of two short home videos, and an HCP questionnaire) in a gradient boosted decision tree machine learning algorithm to produce either an ASD positive, ASD negative, or indeterminate output. This study compared Device outputs to diagnostic agreement by two or more independent specialists in a cohort of 18–72-month-olds with developmental delay concerns (425 study completers, 36% female, 29% ASD prevalence). Device output PPV for all study completers was 80.8% (95% confidence intervals (CI), 70.3%–88.8%) and NPV was 98.3% (90.6%–100%). For the 31.8% of participants who received a determinate output (ASD positive or negative) Device sensitivity was 98.4% (91.6%–100%) and specificity was 78.9% (67.6%–87.7%). The Device’s indeterminate output acts as a risk control measure when inputs are insufficiently granular to make a determinate recommendation with confidence. If this risk control measure were removed, the sensitivity for all study completers would fall to 51.6% (63/122) (95% CI 42.4%, 60.8%), and specificity would fall to 18.5% (56/303) (95% CI 14.3%, 23.3%). Among participants for whom the Device abstained from providing a result, specialists identified that 91% had one or more complex neurodevelopmental disorders. No significant differences in Device performance were found across participants’ sex, race/ethnicity, income, or education level. For nearly a third of this primary care sample, the Device enabled timely diagnostic evaluation with a high degree of accuracy. The Device shows promise to significantly increase the number of children able to be diagnosed with ASD in a primary care setting, potentially facilitating earlier intervention and more efficient use of specialist resources.

Fragile X syndrome (FXS), the most common inherited cause of intellectual disability, learning disability, and autism spectrum disorder, is associated with an increased prevalence of certain medical conditions including seizures. The goal of this study was to better understand seizures in individuals with FXS using the Fragile X Online Registry with Accessible Research Database, a multisite observational study initiated in 2012 involving FXS clinics in the Fragile X Clinic and Research Consortium. Seizure data were available for 1,607 participants, mostly male (77%) and white (74.5%). The overall prevalence of at least one seizure was 12%, with this rate being significantly higher in males than females (13.7 vs. 6.2%, p &lt; 0.001). As compared to individuals with FXS without seizures, those with seizures were more likely to have autism spectrum disorder, current sleep apnea, later acquisition of expressive language, more severe intellectual disability, hyperactivity, irritability, and stereotyped movements. The mean age of seizure onset was 6.4 (SD 6.1) years of age with the great majority (&gt;80%) having onset of seizures which was before 10. For those with epilepsy, about half (52%) had seizures for more than 3 years. This group was found to have greater cognitive and language impairment, but not behavioral disruptions, compared with those with seizures for &lt;3 years. Antiepileptic drugs were more often used in males (60.6%) than females (34.8%), and females more often required more than one medication. The most commonly used anticonvulsants were oxcarbazepine, valproic acid, lamotrigine, and levetiracetam. The current study is the largest and first longitudinal study ever conducted to describe seizures in FXS. Overall, this study confirms previous reports of seizures in FXS and extends previous findings by further defining the cognitive and behavioral phenotype of those with epilepsy in FXS. Future studies should further investigate the natural history of seizures in FXS and the characteristics of seizures in FXS in adulthood.

We performed a retrospective matched case-control study evaluating whether the traditional coagulation profile predicts cerebrovascular events in children on extracorporeal membrane oxygenation (ECMO) in a 71 bed intensive care unit at a tertiary children's hospital. Between 2009 and 2014, 241 neonates and children were initiated on ECMO. The cumulative 5 year incidence of intracranial hemorrhage and infarct was 9.2% and 7.9%, respectively. Thirty-six cases were individually matched 1:1 with control subjects based on age, primary diagnosis, ECMO type, cannulation site, and the presence of pre-ECMO coagulopathy. In-hospital mortality was higher among the cases compared with control subjects (78 vs. 22%, p < 0.01). The median laboratory values that assisted with heparin anticoagulation monitoring (activated clotting time, partial thromboplastin time, and antifactor Xa) and the laboratory data that assisted with blood product administration (platelet count, prothrombin time, fibrinogen, and d-dimer) during the 24 and 72 hour periods before the cerebrovascular event did not show any significant difference between the hemorrhage group and their controls or between the infarct group and their controls. The traditional coagulation profile did not predict acute cerebrovascular events in our cohort. Other markers of neurologic injury on ECMO are yet to be elucidated. Prospective studies to determine better predictors of cerebrovascular complications in pediatric ECMO patients are required.