A large cohort study of prenatal exome sequencing redefines diagnosis in fetal corpus callosum anomalies.

Anomalies of the corpus callosum (AnCC) are congenital malformations associated with highly variable neurodevelopmental outcomes. We performed prenatal Exome Sequencing (pES) on a cohort of 352 fetuses diagnosed with AnCC, analyzing the diagnostic yield, the implicated genes based on the type of anomaly (partial or complete agenesis, short corpus callosum, or callosal dysgenesis) and assessing the impact on pregnancy outcomes. The overall diagnostic yield of pES was 23%, with pathogenic or likely pathogenic variants identified in 49 different genes, most of which linked to intellectual developmental disorders.

Refined genotype-phenotype correlations in neurofibromatosis type 1 patients with point variants.

Background: Neurofibromatosis type 1 (NF1) is one of the most frequent genetic disorders. NF1 is caused by dominant loss-of-function pathogenic variants (PVs) of the tumour-suppressor gene , which encodes neurofibromin, a negative regulator of rat sarcoma proteins. NF1 is an autosomal dominant disorder with complete penetrance, but a highly variable expression.

Oral phenotype in SATB2-associated syndrome: cross-sectional study of the French cohort.

Background: SATB2-associated syndrome (SAS) results from various mutations of the SATB2 gene and associates a neurodevelopmental disorder including major speech delay, intellectual disability, and behavioral problems with dental anomalies, sometimes a cleft palate, risk of osteoporosis, and facial dysmorphism. The principal objective of this study was to describe the oral phenotype of young children with SATB2-associated syndrome, especially in terms of orofacial malformation of Robin Sequence (RS) spectrum (bifid uvula, cleft palate, or RS, dental malformation, feeding and communication, with data from a national cohort. The secondary objective was to determine whether feeding and communication disorders were more severe when associated with an orofacial malformation of RS spectrum.

Bi-allelic variants in TM2D3 cause a severe syndromic neurodevelopmental disorder associated with endoplasmic reticulum and mitochondrial abnormalities.

We identified via exome sequencing bi-allelic variants in TM2D3 in four affected individuals from four unrelated families with overlapping clinical presentations, including microcephaly, severe global developmental delay with absent speech, autistic features, heart malformation, and dysmorphic facial features. TM2D3 encodes a transmembrane protein present in many tissues, with a higher abundance in the central nervous system, but little is known about its function and cell localization. Here, by using chemical and genetically encoded probes in SNB75 cells, we show that TM2D3 is an endoplasmic reticulum (ER) protein.

Androgens mediate sexual dimorphism in Pilarowski-Bjornsson Syndrome.

Sex-specific penetrance in autosomal dominant Mendelian conditions is largely understudied. The neurodevelopmental disorder Pilarowski-Bjornsson syndrome (PILBOS) was initially described in females. Here, we describe the clinical and genetic characteristics of the largest PILBOS cohort to date, showing that both sexes can exhibit PILBOS features, although males are overrepresented.

Dominant variants in major spliceosome U4 and U5 small nuclear RNA genes cause neurodevelopmental disorders through splicing disruption.

The major spliceosome contains five small nuclear RNAs (snRNAs; U1, U2, U4, U5 and U6) essential for splicing. Variants in RNU4-2, encoding U4, cause a neurodevelopmental disorder called ReNU syndrome. We investigated de novo variants in 50 snRNA-encoding genes in a French cohort of 23,649 individuals with rare disorders and gathered additional cases through international collaborations.

C-terminal frameshift variants in GPKOW are associated with a multisystemic X-linked disorder.

Purpose: GPKOW, a gene on the X-chromosome, encodes a nuclear RNA-binding protein important in messenger RNA (mRNA) processing as a spliceosome subunit. This work aims to establish GPKOW as a disease-associated gene.

Methods: We describe 3 males from 2 unrelated families with hemizygous frameshift variants affecting the last exon of GPKOW p.

Reanalysis of unsolved prenatal exome sequencing for structural defects: diagnostic yield and contribution of postnatal/postmortem features.

In 30-40% of fetuses with structural defects, the causal variant remains undiagnosed after karyotype, chromosomal microarray, and exome sequencing. This study presents the results of a reanalysis of unsolved prenatal ES (pES) cases and investigates how postnatal/postmortem phenotyping contributes to identifying relevant variants. pES data was prospectively reanalyzed for unsolved cases enrolled in the AnDDI-Prénatome cohort study.

ARID2-related disorder: further delineation of the clinical phenotype of 27 novel individuals and description of an epigenetic signature.

Rare genetic variants in ARID2 are responsible for a recently described neurodevelopmental condition called ARID2-related disorder (ARID2-RD). ARID2 belongs to PBAF, a unit of the SWI/SNF complex, which is a chromatin remodeling complex. This work aims to further delineate the phenotypic spectrum of ARID2-RD, providing clinicians with additional data for better care and aid in the future diagnosis of this condition.

Combined genomics and proteomics unveils elusive variants and vast aetiologic heterogeneity in dystonia.

Dystonia is a rare disease trait for which large-scale genomic investigations are still underrepresented. Genetic heterogeneity among patients with unexplained dystonia warrants interrogation of entire genome sequences, but this has not yet been systematically evaluated. To significantly enhance our understanding of the genetic contribution to dystonia, we (re)analysed 2874 whole-exome sequencing (WES), 564 whole-genome sequencing (WGS), as well as 80 fibroblast-derived proteomics datasets, representing the output of high-throughput analyses in 1990 patients and 973 unaffected relatives from 1877 families.

Phenotypic Heterogeneity of ADTKD-MUC1 Diagnosed Using VNtyper, a Novel Genetic Technique.

Rationale & Objective: Molecular diagnosis of autosomal dominant tubulointerstitial kidney disease (ADTKD) due to variants in the MUC1 gene has long been challenging because variants lie in a large variable number of tandem repeat (VNTR) region, making identification impossible using standard short-read techniques. Previously, we addressed this diagnostic limitation by developing a computational pipeline named VNtyper for easier reliable detection of MUC1 VNTR pathogenic variants from short-read sequences. This led to unexpected diagnoses of ADTKD-MUC1 among patients with kidney disease referred for genetic testing, which we report here.

Further delineation of the SCAF4-associated neurodevelopmental disorder.

While mostly de novo truncating variants in SCAF4 were recently identified in 18 individuals with variable neurodevelopmental phenotypes, knowledge on the molecular and clinical spectrum is still limited. We assembled data on 50 novel individuals with SCAF4 variants ascertained via GeneMatcher and personal communication. With detailed evaluation of clinical data, in silico predictions and structural modeling, we further characterized the molecular and clinical spectrum of the autosomal dominant SCAF4-associated neurodevelopmental disorder.

Clinical and genetic delineation of autosomal recessive and dominant ACTL6B-related developmental brain disorders.

Purpose: This study aims to comprehensively delineate the phenotypic spectrum of ACTL6B-related disorders, previously associated with both autosomal recessive and autosomal dominant neurodevelopmental disorders. Molecularly, the role of the nucleolar protein ACTL6B in contributing to the disease has remained unclear.

Methods: We identified 105 affected individuals, including 39 previously reported cases, and systematically analyzed detailed clinical and genetic data for all individuals.

Prenatal Diagnosis of Myhre Syndrome in Two Cases: Further Delineation of the Cardiac and External Phenotype.

Myhre syndrome is a rare genetic disease caused by recurrent gain-of-function variants in SMAD4 (Ile500Thr, Ile500Val, Arg496Cys, and Ile500Met) characterized by postnatal short stature with pseudo-muscular build, joint stiffness, variable intellectual disability, hearing loss, and a distinctive pattern of dysmorphic facial features. The course can be severe in some cases, with life-threatening cardiac and pulmonary complications caused by connective tissue involvement. These progressive features over time make early clinical diagnosis difficult but possible by astute clinicians who evaluate young children with autism or short stature and unusual appearance.

PSMD11 loss-of-function variants correlate with a neurobehavioral phenotype, obesity, and increased interferon response.

Primary proteasomopathies have recently emerged as a new class of rare early-onset neurodevelopmental disorders (NDDs) caused by pathogenic variants in the PSMB1, PSMC1, PSMC3, or PSMD12 proteasome genes. Proteasomes are large multi-subunit protein complexes that maintain cellular protein homeostasis by clearing ubiquitin-tagged damaged, misfolded, or unnecessary proteins. In this study, we have identified PSMD11 as an additional proteasome gene in which pathogenic variation is associated with an NDD-causing proteasomopathy.

Heterozygous loss-of-function variants in DOCK4 cause neurodevelopmental delay and microcephaly.

Neurons form the basic anatomical and functional structure of the nervous system, and defects in neuronal differentiation or formation of neurites are associated with various psychiatric and neurodevelopmental disorders. Dynamic changes in the cytoskeleton are essential for this process, which is, inter alia, controlled by the dedicator of cytokinesis 4 (DOCK4) through the activation of RAC1. Here, we clinically describe 7 individuals (6 males and one female) with variants in DOCK4 and overlapping phenotype of mild to severe global developmental delay.

variants underlying X-linked intellectual disability disrupt protein function via distinct mechanisms.

Neurodevelopmental disorders with intellectual disability (ND/ID) are a heterogeneous group of diseases driving lifelong deficits in cognition and behavior with no definitive cure. X-linked intellectual disability disorder 105 (XLID105, #300984; OMIM) is a ND/ID driven by hemizygous variants in the gene encoding a protein deubiquitylase with a role in cell proliferation and neural development. Currently, only four genetically diagnosed individuals from two unrelated families have been described with limited clinical data.