Comprehensive analysis of CNOT3-related neurodevelopmental disorders: phenotypic and genotypic characterization.

The CCR4-NOT complex, crucial in gene expression regulation, includes CNOT3, a subunit linked to neurodevelopmental disorders when mutated. This study investigates 51 patients from 42 families with heterozygous CNOT3 variants, aiming to expand the understanding of CNOT3-related neurodevelopmental disorders and explore genotype-phenotype correlations. Patients originated from various countries, reflecting the disorder's global significance.

Missense variants linked to a neurodevelopmental disorder with intellectual disability, epilepsy, hypoplasia of the corpus callosum, and white matter abnormalities.

The Abelson-interactor 2 gene ( encodes a protein that functions as a regulator of Rac-dependent actin cytoskeleton dynamics, a highly coordinated structural framework essential for maintaining intracellular homeostasis and vital in processes such as cell adhesion, communication, membrane transport, migration, cell growth, and development. As a component of the Rac-1 activated WAVE regulatory complex (WRC), ABI2 initiates the actin polymerization machinery Arp2/3 to drive lamellipodia formation, and underlying key cellular processes such as axonal guidance, cell motility, and cell adhesion. Additionally, ABI2 acts as a substrate for non-receptor tyrosine kinases ABL1 and ABL2, with downstream effects controlling neuronal differentiation and migration involved in neocortical development.

MBOAT7 encephalopathy: Characterizing the neurology and epileptology.

Objective: Biallelic pathogenic MBOAT7 variants are associated with neurodevelopmental disorders, intellectual disability (ID), epilepsy, and neuropsychiatric disorders such as attention-deficit/hyperactivity disorder and autism spectrum disorders. We aimed to characterize the epilepsy phenotype in a cohort of patients affected by this syndrome.

Methods: We describe epilepsy features, electroencephalography, magnetic resonance imaging (MRI) findings, antiseizure treatment response, and neurodevelopment of 15 patients with biallelic MBOAT7 variants.

C12ORF57: a novel principal regulator of synaptic AMPA currents and excitatory neuronal homeostasis.

Objective: Excitatory neuronal homeostasis is crucial for neuronal survival, circuit function, and plasticity. Disruptions in this form of homeostasis are believed to underpin a variety of neuronal conditions including intellectual disability, epilepsy, and autism. However, the underlying genetic and molecular mechanisms maintaining this homeostasis remain poorly understood.

CDK13-Related Disorder: Novel Insights From A Series of 27 Cases and Recommendations for Clinical Management.

In 2016, Sifrim and colleagues described the first group of patients carrying heterozygous pathogenic variants in CDK13 and sharing major clinical features mainly consisting of congenital heart defects, intellectual disability and peculiar facial features (Congenital Heart Defects, Dysmorphic Facial Features, and Intellectual Developmental Disorder; CHDFIDD, OMIM # 617360). This condition is generally referred to as CDK13-related disorder, and since then other reports have provided further clinical and molecular information. Here we describe a group of 27 previously unreported patients to more accurately profile the clinical spectrum associated with CDK13 variants, disclosing novel associated findings, such as complex craniosynostosis and variable skeletal features (e.

Noise induces Ca2+ signaling waves and Chop/S-Xbp1 expression in the hearing cochlea.

Exposure to loud noise is a common cause of acquired hearing loss. Disruption of subcellular calcium homeostasis and downstream stress pathways in the endoplasmic reticulum and mitochondria, including the unfolded protein response (UPR), have been implicated in the pathophysiology of noise-induced hearing loss. However, studies on the association between calcium homeostasis and stress pathways have been limited due to limited ability to measure calcium dynamics in mature-hearing, noise-exposed mice.

Modulating the unfolded protein response with ISRIB mitigates cisplatin ototoxicity.

Cisplatin is a commonly used chemotherapy agent with a nearly universal side effect of sensorineural hearing loss. The cellular mechanisms underlying cisplatin ototoxicity are poorly understood. Efforts in drug development to prevent or reverse cisplatin ototoxicity have largely focused on pathways of oxidative stress and apoptosis.

Noise induces intercellular Ca signaling waves and the unfolded protein response in the hearing cochlea.

Exposure to loud noise is a common cause of acquired hearing loss. Disruption of subcellular calcium homeostasis and downstream stress pathways in the endoplasmic reticulum and mitochondria, including the unfolded protein response, have been implicated in the pathophysiology of noise-induced hearing loss. However, studies on the association between calcium homeostasis and stress pathways has been limited due to limited ability to measure calcium dynamics in mature-hearing, noise-exposed mice.

Discovering the gene-brain-behavior link in autism via generative machine learning.

Autism is traditionally diagnosed behaviorally but has a strong genetic basis. A genetics-first approach could transform understanding and treatment of autism. However, isolating the gene-brain-behavior relationship from confounding sources of variability is a challenge.

Diverse childhood neurologic disorders and outcomes following fetal neurologic consultation.

Fetal neurology encompasses the full spectrum of neonatal and child neurology presentations, with complex additional layers of diagnostic and prognostic challenges unique to the specific prenatal consultation. Diverse genetic and acquired etiologies with a range of potential outcomes may be encountered. Three clinical case presentations are discussed that highlight how postnatal phenotyping and longitudinal follow-up are essential to address the uncertainties that arise in utero, after birth, and in childhood, as well as to provide continuity of care.

Exome copy number variant detection, analysis, and classification in a large cohort of families with undiagnosed rare genetic disease.

Copy number variants (CNVs) are significant contributors to the pathogenicity of rare genetic diseases and, with new innovative methods, can now reliably be identified from exome sequencing. Challenges still remain in accurate classification of CNV pathogenicity. CNV calling using GATK-gCNV was performed on exomes from a cohort of 6,633 families (15,759 individuals) with heterogeneous phenotypes and variable prior genetic testing collected at the Broad Institute Center for Mendelian Genomics of the Genomics Research to Elucidate the Genetics of Rare Diseases consortium and analyzed using the seqr platform.

TMTC4 is a hair cell-specific human deafness gene.

Transmembrane and tetratricopeptide repeat 4 (Tmtc4) is a deafness gene in mice. Tmtc4-KO mice have rapidly progressive postnatal hearing loss due to overactivation of the unfolded protein response (UPR); however, the cellular basis and human relevance of Tmtc4-associated hearing loss in the cochlea was not heretofore appreciated. We created a hair cell-specific conditional KO mouse that phenocopies the constitutive KO with postnatal onset deafness, demonstrating that Tmtc4 is a hair cell-specific deafness gene.

Modulating the Unfolded Protein Response with ISRIB Mitigates Cisplatin Ototoxicity.

Cisplatin is a commonly used chemotherapy agent with a nearly universal side effect of sensorineural hearing loss. The cellular mechanisms underlying cisplatin ototoxicity are poorly understood. Efforts in drug development to prevent or reverse cisplatin ototoxicity have largely focused on pathways of oxidative stress and apoptosis.

Exome copy number variant detection, analysis and classification in a large cohort of families with undiagnosed rare genetic disease.

Copy number variants (CNVs) are significant contributors to the pathogenicity of rare genetic diseases and with new innovative methods can now reliably be identified from exome sequencing. Challenges still remain in accurate classification of CNV pathogenicity. CNV calling using GATK-gCNV was performed on exomes from a cohort of 6,633 families (15,759 individuals) with heterogeneous phenotypes and variable prior genetic testing collected at the Broad Institute Center for Mendelian Genomics of the GREGoR consortium.

The variant landscape and function of DDX3X in cancer and neurodevelopmental disorders.

RNA molecules rely on proteins across their life cycle. DDX3X encodes an X-linked DEAD-box RNA helicase with a Y-linked paralog, DDX3Y. DDX3X is central to the RNA life cycle and is implicated in many conditions, including cancer and the neurodevelopmental disorder DDX3X syndrome.

Stretch-activated ion channel TMEM63B associates with developmental and epileptic encephalopathies and progressive neurodegeneration.

By converting physical forces into electrical signals or triggering intracellular cascades, stretch-activated ion channels allow the cell to respond to osmotic and mechanical stress. Knowledge of the pathophysiological mechanisms underlying associations of stretch-activated ion channels with human disease is limited. Here, we describe 17 unrelated individuals with severe early-onset developmental and epileptic encephalopathy (DEE), intellectual disability, and severe motor and cortical visual impairment associated with progressive neurodegenerative brain changes carrying ten distinct heterozygous variants of TMEM63B, encoding for a highly conserved stretch-activated ion channel.

De novo CLCN3 variants affecting Gly327 cause severe neurodevelopmental syndrome with brain structural abnormalities.

A recent study revealed that monoallelic missense or biallelic loss-of-function variants in the chloride voltage-gated channel 3 (CLCN3) cause neurodevelopmental disorders resulting in brain abnormalities. Functional studies suggested that some missense variants had varying gain-of-function effects on channel activity. Meanwhile, two patients with homozygous frameshift variants showed severe neuropsychiatric disorders and a range of brain structural abnormalities.