Mono-allelic KCNB2 variants lead to a neurodevelopmental syndrome caused by altered channel inactivation.

Ion channels mediate voltage fluxes or action potentials that are central to the functioning of excitable cells such as neurons. The KCNB family of voltage-gated potassium channels (Kv) consists of two members (KCNB1 and KCNB2) encoded by KCNB1 and KCNB2, respectively. These channels are major contributors to delayed rectifier potassium currents arising from the neuronal soma which modulate overall excitability of neurons. In this study, we identified several mono-allelic pathogenic missense variants in KCNB2, in individuals with a neurodevelopmental syndrome with epilepsy and autism in some individuals. Recurrent dysmorphisms included a broad forehead, synophrys, and digital anomalies. Additionally, we selected three variants where genetic transmission has not been assessed, from two epilepsy studies, for inclusion in our experiments. We characterized channel properties of these variants by expressing them in oocytes of Xenopus laevis and conducting cut-open oocyte voltage clamp electrophysiology. Our datasets indicate no significant change in absolute conductance and conductance-voltage relationships of most disease variants as compared to wild type (WT), when expressed either alone or co-expressed with WT-KCNB2. However, variants c.1141A>G (p.Thr381Ala) and c.641C>T (p.Thr214Met) show complete abrogation of currents when expressed alone with the former exhibiting a left shift in activation midpoint when expressed alone or with WT-KCNB2. The variants we studied, nevertheless, show collective features of increased inactivation shifted to hyperpolarized potentials. We suggest that the effects of the variants on channel inactivation result in hyper-excitability of neurons, which contributes to disease manifestations.

Bi-allelic variants in the ESAM tight-junction gene cause a neurodevelopmental disorder associated with fetal intracranial hemorrhage.

The blood-brain barrier (BBB) is an essential gatekeeper for the central nervous system and incidence of neurodevelopmental disorders (NDDs) is higher in infants with a history of intracerebral hemorrhage (ICH). We discovered a rare disease trait in thirteen individuals, including four fetuses, from eight unrelated families associated with homozygous loss-of-function variant alleles of ESAM which encodes an endothelial cell adhesion molecule. The c.115del (p.Arg39Glyfs∗33) variant, identified in six individuals from four independent families of Southeastern Anatolia, severely impaired the in vitro tubulogenic process of endothelial colony-forming cells, recapitulating previous evidence in null mice, and caused lack of ESAM expression in the capillary endothelial cells of damaged brain. Affected individuals with bi-allelic ESAM variants showed profound global developmental delay/unspecified intellectual disability, epilepsy, absent or severely delayed speech, varying degrees of spasticity, ventriculomegaly, and ICH/cerebral calcifications, the latter being also observed in the fetuses. Phenotypic traits observed in individuals with bi-allelic ESAM variants overlap very closely with other known conditions characterized by endothelial dysfunction due to mutation of genes encoding tight junction molecules. Our findings emphasize the role of brain endothelial dysfunction in NDDs and contribute to the expansion of an emerging group of diseases that we propose to rename as "tightjunctionopathies."

Germline variants in tumor suppressor FBXW7 lead to impaired ubiquitination and a neurodevelopmental syndrome.

Neurodevelopmental disorders are highly heterogenous conditions resulting from abnormalities of brain architecture and/or function. FBXW7 (F-box and WD-repeat-domain-containing 7), a recognized developmental regulator and tumor suppressor, has been shown to regulate cell-cycle progression and cell growth and survival by targeting substrates including CYCLIN E1/2 and NOTCH for degradation via the ubiquitin proteasome system. We used a genotype-first approach and global data-sharing platforms to identify 35 individuals harboring de novo and inherited FBXW7 germline monoallelic chromosomal deletions and nonsense, frameshift, splice-site, and missense variants associated with a neurodevelopmental syndrome. The FBXW7 neurodevelopmental syndrome is distinguished by global developmental delay, borderline to severe intellectual disability, hypotonia, and gastrointestinal issues. Brain imaging detailed variable underlying structural abnormalities affecting the cerebellum, corpus collosum, and white matter. A crystal-structure model of FBXW7 predicted that missense variants were clustered at the substrate-binding surface of the WD40 domain and that these might reduce FBXW7 substrate binding affinity. Expression of recombinant FBXW7 missense variants in cultured cells demonstrated impaired CYCLIN E1 and CYCLIN E2 turnover. Pan-neuronal knockdown of the Drosophila ortholog, archipelago, impaired learning and neuronal function. Collectively, the data presented herein provide compelling evidence of an F-Box protein-related, phenotypically variable neurodevelopmental disorder associated with monoallelic variants in FBXW7.

Bi-allelic loss-of-function variants in BCAS3 cause a syndromic neurodevelopmental disorder.

BCAS3 microtubule-associated cell migration factor (BCAS3) is a large, highly conserved cytoskeletal protein previously proposed to be critical in angiogenesis and implicated in human embryogenesis and tumorigenesis. Here, we established BCAS3 loss-of-function variants as causative for a neurodevelopmental disorder. We report 15 individuals from eight unrelated families with germline bi-allelic loss-of-function variants in BCAS3. All probands share a global developmental delay accompanied by pyramidal tract involvement, microcephaly, short stature, strabismus, dysmorphic facial features, and seizures. The human phenotype is less severe compared with the Bcas3 knockout mouse model and cannot be explained by angiogenic defects alone. Consistent with being loss-of-function alleles, we observed absence of BCAS3 in probands' primary fibroblasts. By comparing the transcriptomic and proteomic data based on probands' fibroblasts with those of the knockout mouse model, we identified similar dysregulated pathways resulting from over-representation analysis, while the dysregulation of some proposed key interactors could not be confirmed. Together with the results from a tissue-specific Drosophila loss-of-function model, we demonstrate a vital role for BCAS3 in neural tissue development.

Novel phenotype associated with homozygous likely pathogenic variant in the POP1 gene.

The biallelic variants of the POP1 gene are associated with the anauxetic dysplasia (AAD OMIM 607095), a rare skeletal dysplasia, characterized by prenatal rhizomelic shortening of limbs and generalized joint hypermobility. Affected individuals usually have normal neurodevelopmental milestones. Here we present three cases from the same family with likely pathogenic homozygous POP1 variant and a completely novel phenotype: a girl with global developmental delay and autism, microcephaly, peculiar dysmorphic features and multiple congenital anomalies. Two subsequent pregnancies were terminated due to multiple congenital malformations. Fetal DNA samples revealed the same homozygous variant in the POP1 gene. Expression of the RMRP was reduced in the proband compared with control and slightly reduced in both heterozygous parents, carriers for this variant. To our knowledge, this is the first report of this new phenotype, associated with a novel likely pathogenic variant in POP1. Our findings expand the phenotypic spectrum of POP1-related disorders.

EED related overgrowth: First report of multiple members in a single family.

EED is a core component of polycomb repressive complex 2 (PRC2) with EZH2 and SUZ12. PRC2 has H3K27 methyltransferase activity (HMTase) that catalyzes the addition of up to three methyl groups on histone 3 at lysine residue 27 (H3K27). Germline heterozygous variants in EED, SUZ12, and EZH2 have been identified in patients with overgrowth and multiple dysmorphic features. The clinical manifestations of these syndromes significantly overlap: generalized overgrowth, intellectual disability, and scoliosis. To date, 11 unrelated patients have been published with missense variants in EED at highly conserved amino acids. We report three affected members in a family with a previously reported missense variant. All three affected members manifested very similarly, and this represents a homogenous clinical phenotype associated with EED related intellectual disability and overgrowth. This disorder is appropriately called Cohen-Gibson syndrome.

The diagnostic yield of genetic and metabolic investigations in syndromic and nonsyndromic patients with autism spectrum disorder, global developmental delay, or intellectual disability from a dedicated neurodevelopmental disorders genetics clinic.

First-tier genetic investigations for patients with neurodevelopmental disorders (NDDs) may include chromosomal microarray, Fragile X testing, and screening for inherited metabolic diseases, but most remain undiagnosed upon completion of testing. Here, we report the diagnostic yields of genetic testing for 537 patients with at least one of autism spectrum disorder, global developmental delay, and/or intellectual disability. Patients were assessed in a single neurodevelopmental genetics clinic, and each underwent a standardized history and physical examination. Each patient was characterized as syndromic or nonsyndromic based on clinical features. Our results demonstrate that multigene sequencing (with an NDD gene panel or exome) had a higher diagnostic yield (8%; 95% confidence interval [CI]: 5%, 13%) than chromosomal microarray and Fragile X testing combined (4%; 95% CI: 3%, 7%). Biochemical screening for inherited metabolic diseases had a diagnostic yield of zero. The diagnostic yield of genetic testing was significantly higher for syndromic patients than for nonsyndromic patients (odds ratio [OR] 3.09; 95% CI: 1.46, 6.83) and higher for female patients than for male (OR 3.21; 95% CI: 1.52, 6.82). These results add to the growing evidence supporting a comprehensive genetic evaluation that includes both copy number analysis and sequencing of known NDD genes for patients with NDDs.

Novel NARS2 variants in a patient with early-onset status epilepticus: case study and literature review.

BACKGROUND: NARS2 as a member of aminoacyl-tRNA synthetases was necessary to covalently join a specific tRNA to its cognate amino acid. Biallelic variants in NARS2 were reported with disorders such as Leigh syndrome, deafness, epilepsy, and severe myopathy. CASE PRESENTATION: Detailed clinical phenotypes were collected and the NARS2 variants were discovered by whole exome sequencing and verified by Sanger sequencing. Additionally, 3D protein structure visualization was performed by UCSF Chimera. The proband in our study had early-onset status epilepticus with abnormal EEG and MRI results. She also performed global developmental delay (GDD) and myocardial dysfunction. Next-generation sequencing (NGS) and Sanger sequencing revealed compound heterozygous missense variants [NM_024678.6:exon14: c.1352G > A(p.Arg451His); c.707T > C(p.Phe236Ser)] of the NARS2 gene. The proband develops refractory epilepsy with GDD and hyperlactatemia. Unfortunately, she finally died for status seizures two months later. CONCLUSION: We discovered two novel missense variants of NARS2 in a patient with early-onset status epilepticus and myocardial dysfunction. The NGS enables the patient to be clearly diagnosed as combined oxidative phosphorylation deficiency 24 (COXPD24, OMIM:616,239), and our findings expands the spectrum of gene variants in COXPD24.

The inclusion of adults with intellectual disabilities in health research - challenges, barriers and opportunities: a mixed-method study among stakeholders in England.

BACKGROUND: The study aims to understand system barriers to research participation for people with intellectual disabilities. METHODS: A mixed-methods approach examined the inclusivity of people with intellectual disabilities (IDs) in a random sample of National Institute for Health and Care Research (NIHR) studies conducted in 2019-2020. An online questionnaire (stage 1) was sent to the selected studies lead investigators. An expert by experience panel of 25 people with intellectual disabilities (IDs, stage 2), discussed the stage 1 feedback. Descriptive statistics for quantitative data and thematic analysis for qualitative data was conducted. RESULTS: Of 180 studies reviewed, 131 studies (78%) excluded people with IDs. Of these, 45 (34.3%) study researchers provided feedback. Seven (20%) of the 34 studies which included people with IDs gave feedback. Of all respondents over half felt their study had some relevance to people with IDs. A minority (7.6%) stated their study had no relevance. For a quarter of respondents (23.5%), resource issues were a challenge. Qualitative analysis of both stages produced four overarching themes of Research design and delivery, Informed consent, Resource allocation, and Knowledge and skills. CONCLUSION: Health research continues to exclude people with IDs. Researchers and experts by experience identified non-accessible research design, lack of confidence with capacity and consent processes, limited resources such as time and a need for training as barriers. Ethics committees appear reluctant to include people with cognitive deficits to 'protect' them. People with IDs want to be included in research, not only as participants but also through coproduction.

Adaptive behaviour deficits in individuals with 3q29 deletion syndrome.

BACKGROUND: 3q29 deletion syndrome (3q29del) is associated with a significantly increased risk for neurodevelopmental and neuropsychiatric phenotypes. Mild to moderate intellectual disability (ID) is common in this population, and previous work by our team identified substantial deficits in adaptive behaviour. However, the full profile of adaptive function in 3q29del has not been described nor has it been compared with other genomic syndromes associated with elevated risk for neurodevelopmental and neuropsychiatric phenotypes. METHODS: Individuals with 3q29del (n = 32, 62.5% male) were evaluated using the Vineland Adaptive Behaviour Scales, Third Edition, Comprehensive Parent/Caregiver Form (Vineland-3). We explored the relationship between adaptive behaviour and cognitive function, executive function, and neurodevelopmental and neuropsychiatric comorbidities in our 3q29del study sample, and we compared subjects with 3q29del with published data on fragile X syndrome, 22q11.2 deletion syndrome and 16p11.2 deletion and duplication syndromes. RESULTS: Individuals with 3q29del had global deficits in adaptive behaviour that were not driven by specific weaknesses in any given domain. Individual neurodevelopmental and neuropsychiatric diagnoses had a small effect on adaptive behaviour, and the cumulative number of comorbid diagnoses was significantly negatively associated with Vineland-3 performance. Both cognitive ability and executive function were significantly associated with adaptive behaviour, and executive function was a better predictor of Vineland-3 performance than cognitive ability. Finally, the severity of adaptive behaviour deficits in 3q29del was distinct from previously published data on comparable genomic disorders. CONCLUSIONS: Individuals with 3q29del have significant deficits in adaptive behaviour, affecting all domains assessed by the Vineland-3. Executive function is a better predictor of adaptive behaviour than cognitive ability in this population and suggests that interventions targeting executive function may be an effective therapeutic strategy.

Behavioural phenotype of SYNGAP1-related intellectual disability.

BACKGROUND: SYNGAP1- related intellectual disability (SYNGAP1-ID) is a rare genetic disorder presenting with intellectual disability (ID), epilepsy, maladaptive behaviours and communication challenges. To date, few studies have assessed the context in which these maladaptive behaviours occur. This study aims to investigate the prevalence of problem behaviours, characterise the behavioural phenotype and use well-validated measures to explore variables that maintain the behaviours. METHODS: Our sample includes 19 individuals diagnosed with SYNGAP1-ID and their parents. Parents provided information on behaviours that their children engage in, as well as their general behavioural dispositions. Well-validated measures (e.g., the Repetitive Behaviour Scale-Revised, Sensory Profile-2 and Vineland Adaptive Behaviour Scale) were used. A subset of individuals underwent further direct experimental assessment of their problem behaviour to identify the variables maintaining those problem behaviours. Parental reports were analysed using nonparametric statistical analysis; the direct assessments of individuals' problem behaviour were analysed using visual analysis and validated supplemental measures. RESULTS: All 19 individuals engaged in some form of maladaptive problem behaviour. Ratings of ritualistic, sameness and restricted behaviours measured by the RBS-R were commensurate with individuals diagnosed with idiopathic autism spectrum disorder (ASD) while self-injurious behaviours were endorsed at a higher level in SYNGAP1-ID when compared with idiopathic ASD. The problem behaviours in our cohort of patients with SYNGAP1-ID were maintained by automatic reinforcement and social attention and are positively correlated with atypical sensory responses. CONCLUSIONS: Individuals with SYNGAP1-ID engage in problem behaviours commensurate with other populations (e.g., those with ASD), they exhibit atypical response to sensory stimuli. Problem behaviours were frequently maintained by automatic reinforcement, which may result from a dysregulated sensory system. Children with SYNGAP1-ID may benefit from strategies used in persons with ASD.

Efficacy of early clinical interventions for children with global developmental delay.

OBJECTIVE: To evaluate the efficacy of early clinical interventions for children with global developmental delay. METHODS: A total of 127 initial subjects with GDD met the complete inclusion criteria. Seven cases were excluded due to withdrawal or refusal for follow-up. Eventually, the remaining 120 children were divided into two groups based on different treatment regimens: an experimental group and a control group. Ninety children received individualized treatment in the experimental group, while 30 children, due to various reasons, did not receive inpatient treatment and only underwent home-based intervention therapy in the control group. The developmental progress under different intervention methods was compared, and their clinical effectiveness was analyzed. RESULTS: Both groups of patients showed no significant differences in general characteristics such as gender and age (p > 0.05), demonstrating comparability. The initial comparison of developmental quotient scores in all patients before treatment revealed no significant differences. Post-treatment, there was improvement observed in both groups. However, children in the experimental group exhibited significantly higher scores in gross motor skills, fine motor skills, adaptability, language, and personal-social skills compared to those in the control group (p < 0.05). Additionally, the clinical effective rate in the experimental group was notably higher than that in the control group (p < 0.05). CONCLUSION: The combined use of acupuncture with home-based intervention therapy demonstrates favorable therapeutic outcomes in young children with comprehensive developmental delays. This approach has the potential to enhance gross motor skills, fine motor skills, cognition, language, and overall intellectual development in affected children.

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This article reports on the clinical and genetic characteristics of monozygotic twins with Marshall-Smith syndrome (MRSHSS) due to a mutation in the NFIX gene, along with a review of related literature. Both patients presented with global developmental delays, a prominent forehead, shallow eye sockets, and pectus excavatum. Genetic testing revealed a heterozygous splicing site mutation c.697+1G>A in both children, with parents showing wild-type at this locus. According to the guidelines of the American College of Medical Genetics and Genomics, this mutation is considered likely pathogenic and has not been previously reported in the literature. A review of the literature identified 32 MRSHSS patients with splicing/frameshift mutations. Accelerated bone maturation and moderate to severe global developmental delay/intellectual disability are the primary clinical manifestations of patients with MRSHSS. Genetic testing results are crucial for the diagnosis of this condition.

Clinical characterization of familial 1p36.3 microduplication.

Unlike the 1p36 microdeletion syndrome, which has been extensively described, 1p36.3 microduplications have rarely been reported. We report the two siblings of familial 1p36.3 microduplication, presenting with a severe global developmental delay, epilepsy, and a few dysmorphic features. They were referred to moderate-to-severe developmental delay (DD) and intellectual disability (ID). Both were considered eyelid myoclonus with absence of epilepsy (Jeavons syndrome). The EEG is characterized by widespread 2.5-3.5 Hz spikes and spike slow complex wave, eye closure sensitivity, and photosensitivity. The children has same dysmorphic features, including mild bitemporal narrowing and sloping forehead, sparse eyebrows, hypertelorism, ptosis, strabismus, infraorbital creases, wide nasal bridge with bulbous nasal tip, dystaxia, hallux valgus, and flat feet. Family exome sequencing revealed a maternally inherited 3.2-Mb microduplication of chromosomal band 1p36.3p36.2. However, DNA purified from blood samples of either parent did not find evidence for a microduplication of 1p36 in somatic tissue, indicating that such a mutation might be carried in the germline of the parents as gonadal mosaicism. No other family members of the affected siblings' parents were reported to be affected by the symptoms found.

Heterozygous Variants in KDM4B Lead to Global Developmental Delay and Neuroanatomical Defects.

KDM4B is a lysine-specific demethylase with a preferential activity on H3K9 tri/di-methylation (H3K9me3/2)-modified histones. H3K9 tri/di-demethylation is an important epigenetic mechanism responsible for silencing of gene expression in animal development and cancer. However, the role of KDM4B on human development is still poorly characterized. Through international data sharing, we gathered a cohort of nine individuals with mono-allelic de novo or inherited variants in KDM4B. All individuals presented with dysmorphic features and global developmental delay (GDD) with language and motor skills most affected. Three individuals had a history of seizures, and four had anomalies on brain imaging ranging from agenesis of the corpus callosum with hydrocephalus to cystic formations, abnormal hippocampi, and polymicrogyria. In mice, lysine demethylase 4B is expressed during brain development with high levels in the hippocampus, a region important for learning and memory. To understand how KDM4B variants can lead to GDD in humans, we assessed the effect of KDM4B disruption on brain anatomy and behavior through an in vivo heterozygous mouse model (Kdm4b+/-), focusing on neuroanatomical changes. In mutant mice, the total brain volume was significantly reduced with decreased size of the hippocampal dentate gyrus, partial agenesis of the corpus callosum, and ventriculomegaly. This report demonstrates that variants in KDM4B are associated with GDD/ intellectual disability and neuroanatomical defects. Our findings suggest that KDM4B variation leads to a chromatinopathy, broadening the spectrum of this group of Mendelian disorders caused by alterations in epigenetic machinery.

Clinical and functional heterogeneity associated with the disruption of retinoic acid receptor beta.

PURPOSE: Dominant variants in the retinoic acid receptor beta (RARB) gene underlie a syndromic form of microphthalmia, known as MCOPS12, which is associated with other birth anomalies and global developmental delay with spasticity and/or dystonia. Here, we report 25 affected individuals with 17 novel pathogenic or likely pathogenic variants in RARB. This study aims to characterize the functional impact of these variants and describe the clinical spectrum of MCOPS12. METHODS: We used in vitro transcriptional assays and in silico structural analysis to assess the functional relevance of RARB variants in affecting the normal response to retinoids. RESULTS: We found that all RARB variants tested in our assays exhibited either a gain-of-function or a loss-of-function activity. Loss-of-function variants disrupted RARB function through a dominant-negative effect, possibly by disrupting ligand binding and/or coactivators' recruitment. By reviewing clinical data from 52 affected individuals, we found that disruption of RARB is associated with a more variable phenotype than initially suspected, with the absence in some individuals of cardinal features of MCOPS12, such as developmental eye anomaly or motor impairment. CONCLUSION: Our study indicates that pathogenic variants in RARB are functionally heterogeneous and associated with extensive clinical heterogeneity.

Expanding the genetic spectrum of ALKU syndrome: Compound heterozygosity for two deleterious variants in SMG8 gene.

Alzahrani-Kuwahara syndrome (ALKUS) is a neurodevelopmental disorder that includes microcephaly, facial dysmorphism, and variable congenital and eye malformations. We present the first case of ALKUS described in the European population caused by two variants in compound heterozygosity of the gene SMG8. We present a patient with two variants in compound heterozygosity in the SMG8 gene identified by in trio whole exome sequencing based in next generation sequencing (xGEN® Exome Research Panel, Nextseq550 platform). International case reporting (CARE) criteria were followed. Patient written consent was obtained through legal responsible persons. We describe a 27-year-old male, the second child of a healthy and non-consanguineous couple, whose genetic analysis showed two variants in compound heterozygosity, c.1159C > T (p.Arg387*) and c.2407del (p.Arg803Glyfs*10), in the SMG8 gene, both classified as likely pathogenic. As described by Fatema Alzahrani et al. in a series of eight patients, our patient had global developmental delay with impaired intellectual development, facial dysmorphism, and limb disproportion. Additionally, our patient had lower limb spastic paraparesis, marked osteotendinous hyperreflexia with extensor plantar response bilaterally and paretic gait. Our patient resembles the phenotype described by Fatema Alzahrani et al., however, he is the first patient with two SMG8 deleterious variants in compound heterozygosity, and the first to exhibit pyramidal signs and gait disorder as part of the phenotype.

A nonsense variant in the N-terminal acetyltransferase NAA30 may be associated with global developmental delay and tracheal cleft.

Most human proteins are N-terminally acetylated by N-terminal acetyltransferases (NATs), which play crucial roles in many cellular functions. The NatC complex, comprising the catalytic subunit NAA30 and the auxiliary subunits NAA35 and NAA38, is estimated to acetylate up to 20% of the human proteome in a co-translational manner. Several NAT enzymes have been linked to rare genetic diseases, causing developmental delay, intellectual disability, and heart disease. Here, we report a de novo heterozygous NAA30 nonsense variant c.244C>T (p.Q82*) (NM_001011713.2), which was identified by whole exome sequencing in a 5-year-old boy presenting with global development delay, autism spectrum disorder, hypotonia, tracheal cleft, and recurrent respiratory infections. Biochemical studies were performed to assess the functional impact of the premature stop codon on NAA30's catalytic activity. We find that NAA30-Q82* completely disrupts the N-terminal acetyltransferase activity toward a classical NatC substrate using an in vitro acetylation assay. This finding corresponds with structural modeling showing that the truncated NAA30 variant lacks the entire GNAT domain, which is required for catalytic activity. This study suggests that defective NatC-mediated N-terminal acetylation can cause disease, thus expanding the spectrum of NAT variants linked to genetic disease.

Haemophilia B, severe childhood obesity and other extra-haematological features associated with similar 4Mb-deletions on Xq27: Clinical findings, molecular insights and literature update.

INTRODUCTION: Haemophilia B (HB) is associated with pathogenic variants in F9. Hemizygous deletions encompassing the entire F9 and proximate genes may express extra-haematological clinical phenotypes. AIM: To analyse the genotype/phenotype correlations in two unrelated boys with severe early childhood obesity (SCO), global developmental delay (GDD) and similar bleeding phenotype associated with comparable Xq27 deletions spanning the entire F9 and proximate genes, and characterise the pathogenic events estimating the most likely mutational mechanism involved. METHODS: Entire F9-deletions were detected in three hemizygous unrelated probands with HB: two cases, C#1/C#2, presented SCO and GDD and a control patient (Co), who only had severe bleeding symptoms. Dense SNP-array and case-specific STS walking scan allowed characterisation of the deletion breakpoints. Extensive use of bioinformatics, statistics and clinical databases allowed the investigation of genotype-phenotype associations. RESULTS: Patients C#1/C#2 and Co resulted in a complete F9 and additional gene deletions of variable extensions on Xq26.3-Xq27.2 (C#1/C#2/Co: 4.3Mb/3.9Mb/160Kb). C#1/C#2 common deleted gene SOX3 is directly associated with SCO, GDD and pituitary hypothyroidism (PH) whilst C#2 extra-deleted gene MAGEC2 indirectly relates to anal atresia (AA). Breakpoint analysis revealed the involvement of the mechanisms of Alu/Alu recombination for the first time in HB and non-homologous or alternative end-joining. CONCLUSION: Our results represent the first report of unrelated patients with HB, SCO and GDD. This study and the literature update expand the spectrum of clinical findings and molecular insights observed in patients with HB caused by complete F9 and nearby SOX3 and MAGEC2 gene deletions, which may configure a contiguous gene syndrome.

Health disparities associated with access to disability evaluations for toddlers in Early Head Start.

BACKGROUND: The aim of this investigation was to examine developmental, sociodemographic and familial factors associated with parent reported access to an evaluation in an Early Head Start sample. Children with developmental disabilities often require evaluations to access early interventions, which can improve their long-term outcomes. METHODS: This study (n = 191) examined how developmental, sociodemographic and parent factors at age 2 were associated with parent reporting the child being evaluated by age 3. Two logistic regression analyses were conducted. The first model included children at age 2 with scores at least in the monitoring zone of developmental risk, and the second model included children with high developmental risk. RESULTS: The first model found that children in the monitoring zone of developmental risk were more likely to be evaluated per parent report if they were born preterm, male, with increased behaviour problems, higher economic risk, increased maternal education, increased parental depressive symptoms and in urban areas and less likely if they were of Black or Hispanic/Latino ethnicity, had no health insurance or more home disorganisation. The second model found that children with high developmental risk were less likely to be evaluated per parent report if they were female, of Hispanic/Latino ethnicity, had better language skills and increased home disorganisation and more likely if their parents reported increased depressive symptoms or less economic risk. CONCLUSIONS: This study highlights barriers associated with access to developmental and disability evaluations for children in at-risk families. Health disparities are negatively associated with children's access to evaluations, even when supported by systems like Early Head Start.