CUL3-related neurodevelopmental disorder: Clinical phenotype of 20 new individuals and identification of a potential phenotype-associated episignature.

Neurodevelopmental disorder with or without autism or seizures (NEDAUS) is a neurodevelopmental disorder characterized by global developmental delay, speech delay, seizures, autistic features, and/or behavior abnormalities. It is caused by CUL3 (Cullin-3 ubiquitin ligase) haploinsufficiency. We collected clinical and molecular data from 26 individuals carrying pathogenic variants and variants of uncertain significance (VUS) in the CUL3 gene, including 20 previously unreported cases.

Identification of a pathogenic deep intronic variant in ATRX ends a diagnostic odyssey.

Variation in the non-coding genome is being increasingly recognized to be involved in monogenic disease etiology. However, the interpretation of non-coding variation is complicated by a lack of understanding of how non-coding genetic elements function. Additional lines of evidence are therefore needed to recognize non-coding variants as pathogenic.

Loss-of-function of activity-dependent neuroprotective protein (ADNP) by a splice-acceptor site mutation causes Helsmoortel-Van der Aa syndrome.

Mutations in ADNP result in Helsmoortel-Van der Aa syndrome. Here, we describe the first de novo intronic deletion, affecting the splice-acceptor site of the first coding ADNP exon in a five-year-old girl with developmental delay and autism. Whereas exome sequencing failed to detect the non-coding deletion, genome-wide CpG methylation analysis revealed an episignature suggestive of a Helsmoortel-Van der Aa syndrome diagnosis.

Diagnostic utility and reporting recommendations for clinical DNA methylation episignature testing in genetically undiagnosed rare diseases.

Purpose: This study aims to assess the diagnostic utility and provide reporting recommendations for clinical DNA methylation episignature testing based on the cohort of patients tested through the EpiSign Clinical Testing Network.

Methods: The EpiSign assay utilized unsupervised clustering techniques and a support vector machine-based classification algorithm to compare each patient's genome-wide DNA methylation profile with the EpiSign Knowledge Database, yielding the result that was reported. An international working group, representing distinct EpiSign Clinical Testing Network health jurisdictions, collaborated to establish recommendations for interpretation and reporting of episignature testing.

Neurodevelopmental and other phenotypes recurrently associated with heterozygous BAZ2B loss-of-function variants.

The bromodomain adjacent to zinc finger 2B (BAZ2B) gene encodes a chromatin remodeling protein that has been shown to perform a variety of regulatory functions. It has been proposed that loss of BAZ2B function is associated with neurodevelopmental phenotypes, and some recurrent structural birth defects and dysmorphic features have been documented among individuals carrying heterozygous loss-of-function BAZ2B variants. However, additional evidence is needed to confirm that these phenotypes are attributable to BAZ2B deficiency.

TRAPPC6B biallelic variants cause a neurodevelopmental disorder with TRAPP II and trafficking disruptions.

Highly conserved transport protein particle (TRAPP) complexes regulate subcellular trafficking pathways. Accurate protein trafficking has been increasingly recognized to be critically important for normal development, particularly in the nervous system. Variants in most TRAPP complex subunits have been found to lead to neurodevelopmental disorders with diverse but overlapping phenotypes.

De novo missense variants in phosphatidylinositol kinase PIP5KIγ underlie a neurodevelopmental syndrome associated with altered phosphoinositide signaling.

Phosphoinositides (PIs) are membrane phospholipids produced through the local activity of PI kinases and phosphatases that selectively add or remove phosphate groups from the inositol head group. PIs control membrane composition and play key roles in many cellular processes including actin dynamics, endosomal trafficking, autophagy, and nuclear functions. Mutations in phosphatidylinositol 4,5 bisphosphate [PI(4,5)P2] phosphatases cause a broad spectrum of neurodevelopmental disorders such as Lowe and Joubert syndromes and congenital muscular dystrophy with cataracts and intellectual disability, which are thus associated with increased levels of PI(4,5)P2.

De novo PHF5A variants are associated with craniofacial abnormalities, developmental delay, and hypospadias.

Purpose: The SF3B splicing complex is composed of SF3B1-6 and PHF5A. We report a developmental disorder caused by de novo variants in PHF5A.

Methods: Clinical, genomic, and functional studies using subject-derived fibroblasts and a heterologous cellular system were performed.

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.

DNA methylation episignature and comparative epigenomic profiling of HNRNPU-related neurodevelopmental disorder.

Purpose: HNRNPU haploinsufficiency is associated with developmental and epileptic encephalopathy 54. This neurodevelopmental disorder is characterized by developmental delay, intellectual disability, speech impairment, and early-onset epilepsy. We performed genome-wide DNA methylation (DNAm) analysis in a cohort of individuals to develop a diagnostic biomarker and gain functional insights into the molecular pathophysiology of HNRNPU-related disorder.

Variant Location Is a Novel Risk Factor for Individuals With Arrhythmogenic Cardiomyopathy Due to a Desmoplakin () Truncating Variant.

Background: Truncating variants in desmoplakin (tv) are an important cause of arrhythmogenic cardiomyopathy; however the genetic architecture and genotype-specific risk factors are incompletely understood. We evaluated phenotype, risk factors for ventricular arrhythmias, and underlying genetics of tv cardiomyopathy.

Methods: Individuals with tv and any cardiac phenotype, and their gene-positive family members were included from multiple international centers.

European Respiratory Society statement on familial pulmonary fibrosis.

Genetic predisposition to pulmonary fibrosis has been confirmed by the discovery of several gene mutations that cause pulmonary fibrosis. Although genetic sequencing of familial pulmonary fibrosis (FPF) cases is embedded in routine clinical practice in several countries, many centres have yet to incorporate genetic sequencing within interstitial lung disease (ILD) services and proper international consensus has not yet been established. An international and multidisciplinary expert Task Force (pulmonologists, geneticists, paediatrician, pathologist, genetic counsellor, patient representative and librarian) reviewed the literature between 1945 and 2022, and reached consensus for all of the following questions: 1) Which patients may benefit from genetic sequencing and clinical counselling? 2) What is known of the natural history of FPF? 3) Which genes are usually tested? 4) What is the evidence for telomere length measurement? 5) What is the role of common genetic variants (polymorphisms) in the diagnostic workup? 6) What are the optimal treatment options for FPF? 7) Which family members are eligible for genetic sequencing? 8) Which clinical screening and follow-up parameters may be considered in family members? Through a robust review of the literature, the Task Force offers a statement on genetic sequencing, clinical management and screening of patients with FPF and their relatives.

Persistent Müllerian duct syndrome associated with genetic defects in the regulatory subunit of myosin phosphatase.

Study Question: Can mutations of genes other than AMH or AMHR2, namely PPP1R12A coding myosin phosphatase, lead to persistent Müllerian duct syndrome (PMDS)?

Summary Answer: The detection of PPP1R12A truncation mutations in five cases of PMDS suggests that myosin phosphatase is involved in Müllerian regression, independently of the anti-Müllerian hormone (AMH) signaling cascade.

What Is Known Already: Mutations of AMH and AMHR2 are detectable in an overwhelming majority of PMDS patients but in 10% of cases, both genes are apparently normal, suggesting that other genes may be involved.

Study Design, Size, Duration: DNA samples from 39 PMDS patients collected from 1990 to present, in which Sanger sequencing had failed to detect biallelic AMH or AMHR2 mutations, were screened by massive parallel sequencing.

Reclassification of a likely pathogenic Dutch founder variant in KCNH2; implications of reduced penetrance.

Background: Variants in KCNH2, encoding the human ether a-go-go (hERG) channel that is responsible for the rapid component of the cardiac delayed rectifier K+ current (IKr), are causal to long QT syndrome type 2 (LQTS2). We identified eight index patients with a new variant of unknown significance (VUS), KCNH2:c.2717C > T:p.

Genetic testing in interstitial lung disease: An international survey.

Background And Objective: Genetic analysis is emerging for interstitial lung diseases (ILDs); however, ILD practices are not yet standardized. We surveyed patients', relatives' and pulmonologists' experiences and needs on genetic testing in ILD to evaluate the current situation and identify future needs.

Methods: A clinical epidemiologist (MT) together with members of the ERS taskforce and representatives of the European Idiopathic Pulmonary Fibrosis and related disorders Federation (EU-IPFF) patient organisation developed a survey for patients, relatives and pulmonologists.

Loss-of-function variants in SRRM2 cause a neurodevelopmental disorder.

Purpose: SRRM2 encodes the SRm300 protein, a splicing factor of the SR-related protein family characterized by its serine- and arginine-enriched domains. It promotes interactions between messenger RNA and the spliceosome catalytic machinery. This gene, predicted to be highly intolerant to loss of function (LoF) and very conserved through evolution, has not been previously reported in constitutive human disease.

Telomere dysfunction implicates POT1 in patients with idiopathic pulmonary fibrosis.

Exonic sequencing identified a family with idiopathic pulmonary fibrosis (IPF) containing a previously unreported heterozygous mutation in POT1 p.(L259S). The family displays short telomeres and genetic anticipation.

Expanding the genotype and phenotype spectrum of SYT1-associated neurodevelopmental disorder.

Purpose: Synaptotagmin-1 (SYT1) is a critical mediator of neurotransmitter release in the central nervous system. Previously reported missense SYT1 variants in the C2B domain are associated with severe intellectual disability, movement disorders, behavioral disturbances, and electroencephalogram abnormalities. In this study, we expand the genotypes and phenotypes and identify discriminating features of this disorder.

Pulmonary fibrosis in non-mutation carriers of families with short telomere syndrome gene mutations.

Background And Objective: Diagnostic and predictive genetic testing for disease cause and risk estimation is common in many countries. For genetic diseases, predictive test results are commonly straightforward: presence of the mutation involves increased risk for disease and absence of the mutation involves no inherit risk for disease. Germline mutations in telomere-related genes (TRGs) can lead to telomere shortening and are associated with short telomere syndrome (STS).

Variants in GNAI1 cause a syndrome associated with variable features including developmental delay, seizures, and hypotonia.

Purpose: Neurodevelopmental disorders (NDDs) encompass a spectrum of genetically heterogeneous disorders with features that commonly include developmental delay, intellectual disability, and autism spectrum disorders. We sought to delineate the molecular and phenotypic spectrum of a novel neurodevelopmental disorder caused by variants in the GNAI1 gene.

Methods: Through large cohort trio-based exome sequencing and international data-sharing, we identified 24 unrelated individuals with NDD phenotypes and a variant in GNAI1, which encodes the inhibitory Gαi1 subunit of heterotrimeric G-proteins.

Genetic Evaluation in a Cohort of 126 Dutch Pulmonary Arterial Hypertension Patients.

Pulmonary arterial hypertension (PAH) is a severe, life-threatening disease, and in some cases is caused by genetic defects. This study sought to assess the diagnostic yield of genetic testing in a Dutch cohort of 126 PAH patients. Historically, genetic testing in the Netherlands consisted of the analysis of BMPR2 and SMAD9.

Recessive null-allele variants in MAG associated with spastic ataxia, nystagmus, neuropathy, and dystonia.

Introduction: The gene encoding myelin-associated glycoprotein (MAG) has been implicated in autosomal-recessive spastic paraplegia type 75. To date, only four families with biallelic missense variants in MAG have been reported. The genotypic and phenotypic spectrum of MAG-associated disease awaits further elucidation.