A Deep Intronic Splice Variant in COL1A1 Causing Osteogenesis Imperfecta Type II.

Osteogenesis imperfecta (OI) is a rare disease, hallmarked by bone fragility, multiple fractures, and deformities, and is commonly caused by pathogenic variants in the genes encoding type I collagen. Type II OI is the most severe form and is lethal in the perinatal period. Here, we report recurrence of perinatal lethal OI in two fetuses due to parental mosaicism for a deep intronic pathogenic variant at c.

Refining the 9q34.3 microduplication syndrome reveals mild neurodevelopmental features associated with a distinct global DNA methylation profile.

Precise regulation of gene expression is important for correct neurodevelopment. 9q34.3 deletions affecting the EHMT1 gene result in a syndromic neurodevelopmental disorder named Kleefstra syndrome.

Reanalysis of whole-exome sequencing (WES) data of children with neurodevelopmental disorders in a standard patient care context.

Unlabelled: This study aims to inform future genetic reanalysis management by evaluating the yield of whole-exome sequencing (WES) reanalysis in standard patient care in the Netherlands. Single-center data of 159 patients with a neurodevelopmental disorder (NDD), in which WES analysis and reanalysis were performed between January 1, 2014, and December 31, 2021, was retrospectively collected. Patients were included if they were under the age of 18 years at initial analysis and if this initial analysis did not result in a diagnosis.

-associated Chung-Jansen syndrome: Report of 23 new individuals.

In 2016 and 2018, Chung, Jansen and others described a new syndrome caused by haploinsufficiency of (pleckstrin homology domain interacting protein, OMIM *612,870) and mainly characterized by developmental delay (DD), learning difficulties/intellectual disability (ID), behavioral abnormalities, facial dysmorphism and obesity (CHUJANS, OMIM #617991). So far, alterations appear to be a rare cause of DD/ID. "Omics" technologies such as exome sequencing or array analyses have led to the identification of distinct types of alterations of , including, truncating variants, missense substitutions, splice variants and large deletions encompassing portions of the gene or the entire gene as well as adjacent genomic regions.

Erratum: Variants in cause a spectrum of X-linked neurodevelopmental disorders and facial dysmorphology.

[This corrects the article DOI: 10.1016/j.xhgg.

Biallelic loss of LDB3 leads to a lethal pediatric dilated cardiomyopathy.

Autosomal dominant variants in LDB3 (also known as ZASP), encoding the PDZ-LIM domain-binding factor, have been linked to a late onset phenotype of cardiomyopathy and myofibrillar myopathy in humans. However, despite knockout mice displaying a much more severe phenotype with premature death, bi-allelic variants in LDB3 have not yet been reported. Here we identify biallelic loss-of-function variants in five unrelated cardiomyopathy families by next-generation sequencing.

The Phenotypic Continuum of -Related Disorders.

Background And Objectives: is associated with a broad spectrum of predominantly neurologic disorders, which continues to expand beyond the initially defined phenotypes of alternating hemiplegia of childhood, rapid-onset dystonia parkinsonism, and cerebellar ataxia, areflexia, pes cavus, optic atrophy, sensorineural hearing loss syndrome. This phenotypic variability makes it challenging to assess the pathogenicity of an variant found in an undiagnosed patient. We describe the phenotypic features of individuals carrying a pathogenic/likely pathogenic variant and perform a literature review of all variants published thus far in association with human neurologic disease.

Sacral abnormalities including caudal appendage, skeletal dysplasia, and prenatal cardiomyopathy associated with a pathogenic TAB2 variant in a 3-generation family.

Haplo-insufficiency of the TGFβ-activated kinase 1 binding protein 2 (TAB2) gene is associated with short stature, facial dysmorphisms, connective tissue abnormalities, hearing loss, and cardiac disease. Skeletal dysplasia and sacral dimples are also found in a minority of patients. Here, we describe a 3-generation family with caudal appendage, other sacral anomalies, and skeletal abnormalities including hypoplasia of the iliac wings and scapulae, fusion of the carpal bones and stenosis of the spinal canal, as well as a remarkable course of prenatally-detected cardiomyopathy with characteristics changing over time.

Expansion and mechanistic insights into de novo DEAF1 variants in DEAF1-associated neurodevelopmental disorders.

De novo deleterious and heritable biallelic mutations in the DNA binding domain (DBD) of the transcription factor deformed epidermal autoregulatory factor 1 (DEAF1) result in a phenotypic spectrum of disorders termed DEAF1-associated neurodevelopmental disorders (DAND). RNA-sequencing using hippocampal RNA from mice with conditional deletion of Deaf1 in the central nervous system indicate that loss of Deaf1 activity results in the altered expression of genes involved in neuronal function, dendritic spine maintenance, development, and activity, with reduced dendritic spines in hippocampal regions. Since DEAF1 is not a dosage-sensitive gene, we assessed the dominant negative activity of previously identified de novo variants and a heritable recessive DEAF1 variant on selected DEAF1-regulated genes in 2 different cell models.

Diagnostic Value of a Protocolized In-Depth Evaluation of Pediatric Bone Marrow Failure: A Multi-Center Prospective Cohort Study.

Background: Severe multilineage cytopenia in childhood caused by bone marrow failure (BMF) often represents a serious condition requiring specific management. Patients are at risk for invasive infections and bleeding complications. Previous studies report low rates of identifiable causes of pediatric BMF, rendering most patients with a descriptive diagnosis such as aplastic anemia (AA).

Biallelic Variants in the Ectonucleotidase ENTPD1 Cause a Complex Neurodevelopmental Disorder with Intellectual Disability, Distinct White Matter Abnormalities, and Spastic Paraplegia.

Objective: Human genomics established that pathogenic variation in diverse genes can underlie a single disorder. For example, hereditary spastic paraplegia is associated with >80 genes, with frequently only few affected individuals described for each gene. Herein, we characterize a large cohort of individuals with biallelic variation in ENTPD1, a gene previously linked to spastic paraplegia 64 (Mendelian Inheritance in Man # 615683).

Variants in cause a spectrum of X-linked neurodevelopmental disorders and facial dysmorphology.

Loss-of-function variants in () cause Siderius X-linked intellectual disability (ID) syndrome, hereafter called PHF8-XLID. PHF8 is a histone demethylase that is important for epigenetic regulation of gene expression. PHF8-XLID is an under-characterized disorder with only five previous reports describing different predicted loss-of-function variants in eight individuals.

Biallelic ADAM22 pathogenic variants cause progressive encephalopathy and infantile-onset refractory epilepsy.

Pathogenic variants in A Disintegrin And Metalloproteinase (ADAM) 22, the postsynaptic cell membrane receptor for the glycoprotein leucine-rich repeat glioma-inactivated protein 1 (LGI1), have been recently associated with recessive developmental and epileptic encephalopathy. However, so far, only two affected individuals have been described and many features of this disorder are unknown. We refine the phenotype and report 19 additional individuals harbouring compound heterozygous or homozygous inactivating ADAM22 variants, of whom 18 had clinical data available.

De novo variants in ATP2B1 lead to neurodevelopmental delay.

Calcium (Ca) is a universal second messenger involved in synaptogenesis and cell survival; consequently, its regulation is important for neurons. ATPase plasma membrane Ca transporting 1 (ATP2B1) belongs to the family of ATP-driven calmodulin-dependent Ca pumps that participate in the regulation of intracellular free Ca. Here, we clinically describe a cohort of 12 unrelated individuals with variants in ATP2B1 and an overlapping phenotype of mild to moderate global development delay.

Consolidation of the clinical and genetic definition of a related neurodevelopmental syndrome.

Background: A neurodevelopmental syndrome was recently reported in four patients with heterozygous missense variants in the high-mobility-group (HMG) DNA-binding domain. The present study aimed to consolidate clinical and genetic knowledge of this syndrome.

Methods: We newly identified 17 patients with variants, predicted variant pathogenicity using in silico tests and in vitro functional assays and analysed the patients' phenotypes.

Recurrent de novo missense variants across multiple histone H4 genes underlie a neurodevelopmental syndrome.

Chromatin is essentially an array of nucleosomes, each of which consists of the DNA double-stranded fiber wrapped around a histone octamer. This organization supports cellular processes such as DNA replication, DNA transcription, and DNA repair in all eukaryotes. Human histone H4 is encoded by fourteen canonical histone H4 genes, all differing at the nucleotide level but encoding an invariant protein.

missense mutations in Xia-Gibbs syndrome.

Xia-Gibbs syndrome (XGS; MIM: 615829) is a phenotypically heterogeneous neurodevelopmental disorder (NDD) caused by newly arising mutations in the AT-Hook DNA-Binding Motif-Containing 1 () gene that are predicted to lead to truncated AHDC1 protein synthesis. More than 270 individuals have been diagnosed with XGS worldwide. Despite the absence of an independent assay for AHDC1 protein function to corroborate potential functional consequences of rare variant genetic findings, there are also reports of individuals with XGS-like trait manifestations who have missense mutations and who have been provided a molecular diagnosis of the disorder.

Two Variants Causing Basan Syndrome in a Canadian and a Dutch Family.

Basan syndrome is an autosomal dominant genodermatosis characterized by congenital adermatoglyphia, transient congenital facial milia, neonatal acral bullae, and absent or reduced sweating. Basan syndrome is rare and has been reported in only 10 kindreds worldwide. It is caused by variants in the skin-specific isoform of which starts with an alternative exon 1.

Further delineation of phenotypic spectrum of SCN2A-related disorder.

SCN2A-related disorders include intellectual disability, autism spectrum disorder, seizures, episodic ataxia, and schizophrenia. In this study, the phenotype-genotype association in SCN2A-related disorders was further delineated by collecting detailed clinical and molecular characteristics. Using previously proposed genotype-phenotype hypotheses based on variant function and position, the potential of phenotype prediction from the variants found was examined.

Related Developmental and Epileptic Encephalopathy: Phenotypic and Genotypic Spectrum.

Background And Objectives: Purine-rich element-binding protein A () gene encodes Pur-α, a conserved protein essential for normal postnatal brain development. Recently, a syndrome characterized by intellectual disability, hypotonia, epilepsy, and dysmorphic features was suggested. The aim of this study was to define and expand the phenotypic spectrum of syndrome by collecting data, including EEG, from a large cohort of affected patients.

Deficiency of TET3 leads to a genome-wide DNA hypermethylation episignature in human whole blood.

TET3 encodes an essential dioxygenase involved in epigenetic regulation through DNA demethylation. TET3 deficiency, or Beck-Fahrner syndrome (BEFAHRS; MIM: 618798), is a recently described neurodevelopmental disorder of the DNA demethylation machinery with a nonspecific phenotype resembling other chromatin-modifying disorders, but inconsistent variant types and inheritance patterns pose diagnostic challenges. Given TET3's direct role in regulating 5-methylcytosine and recent identification of syndrome-specific DNA methylation profiles, we analyzed genome-wide DNA methylation in whole blood of TET3-deficient individuals and identified an episignature that distinguishes affected and unaffected individuals and those with mono-allelic and bi-allelic pathogenic variants.