Pathogenic XPO1 variants cause a dominant neurodevelopmental disorder.

Purpose: XPO1 functions in key cellular processes, including nucleo-cytoplasmic export and mitosis. The gene is deleted in a subset of patients with the 2p15p16.1 microdeletion syndrome, however no monogenic XPO1-related disorder has been described to date.

Analysis of R-loop forming regions identifies RNU2-2 and RNU5B-1 as neurodevelopmental disorder genes.

R-loops are DNA-RNA hybrid structures that may promote mutagenesis. However, their contribution to human Mendelian disorders is unexplored. Here we show excess de novo variants in genomic regions that form R-loops (henceforth, 'R-loop regions') and demonstrate enrichment of R-loop region variants (RRVs) in ribozyme, snoRNA and snRNA genes, specifically in rare disease cohorts.

Evaluating the return of additional findings from the 100,000 Genomes Project: A mixed methods study exploring participant experiences of receiving secondary findings from genomic sequencing.

Purpose: 100,000 Genomes Project participants could consent to receive additional findings (AFs) for variants associated with susceptibility to cancer and familial hypercholesterolemia (FH). Here we evaluate stakeholder experiences to inform clinical practice.

Methods: Mixed-methods study conducted at 18 sites across England that comprised a cross-sectional survey and interviews with participants who received a positive AF (PAF), and interviews with participants who had no AFs (NAF).

Family mapping of previously identified patients with pathogenic or likely pathogenic variants using predictive genotyping and detailed phenotyping approach: the FAME case-control study.

Hypophosphatasia (HPP) is an inborn error of metabolism caused by loss-of-function variants in the gene, which encodes the tissue nonspecific isozyme of alkaline phosphatase (ALP). There is no typical phenotype in adults. We used a genotyping first approach to determine whether pathogenic variants were associated with musculoskeletal symptoms, mineral metabolism abnormalities, and an impact on quality of life.

Large-scale evaluation of outcomes after a genetic diagnosis in children with severe developmental disorders.

Purpose: We sought to evaluate outcomes for clinical management after a genetic diagnosis from the Deciphering Developmental Disorders study.

Methods: Individuals in the Deciphering Developmental Disorders study who had a pathogenic/likely pathogenic genotype in the DECIPHER database were selected for inclusion ( = 5010). Clinical notes from regional clinical genetics services notes were reviewed to assess predefined clinical outcomes relating to interventions, prenatal choices, and information provision.

Aarskog-Scott syndrome: a clinical study based on a large series of 111 male patients with a pathogenic variant in and management recommendations.

Background: Aarskog-Scott syndrome (AAS) is a rare condition with multiple congenital anomalies, caused by hemizygote variants in the gene. Its description was based mostly on old case reports, in whom a molecular diagnosis was not always available, or on small series. The aim of this study was to better delineate the phenotype and the natural history of AAS and to provide clues for the diagnosis and the management of the patients.

"I'm quite proud of how we've handled it": health professionals' experiences of returning additional findings from the 100,000 genomes project.

Participants in the 100,000 Genomes Project (100kGP) could consent to receive additional finding (AF) results, individual variants relating to genes associated with susceptibility to cancer and familial hypercholesterolemia (FH). In the study reported here, qualitative interviews were used to explore the experiences of National Health Service (NHS) professionals from across England who were tasked with returning over 80,000 "no AF" results and 700 positive AF results to 100kGP participants. Interviews were conducted with 45 professionals from a range of backgrounds, including Genetic Counsellors, Clinical Geneticists, FH Clinical Nurse Specialists and Clinical Scientists.

Comprehensive EHMT1 variants analysis broadens genotype-phenotype associations and molecular mechanisms in Kleefstra syndrome.

The shift to a genotype-first approach in genetic diagnostics has revolutionized our understanding of neurodevelopmental disorders, expanding both their molecular and phenotypic spectra. Kleefstra syndrome (KLEFS1) is caused by EHMT1 haploinsufficiency and exhibits broad clinical manifestations. EHMT1 encodes euchromatic histone methyltransferase-1-a pivotal component of the epigenetic machinery.

Clinical and molecular characterization of patients with YWHAG-related epilepsy.

Objective: YWHAG variant alleles have been associated with a rare disease trait whose clinical synopsis includes an early onset epileptic encephalopathy with predominantly myoclonic seizures, developmental delay/intellectual disability, and facial dysmorphisms. Through description of a large cohort, which doubles the number of reported patients, we further delineate the spectrum of YWHAG-related epilepsy.

Methods: We included in this study 24 patients, 21 new and three previously described, with pathogenic/likely pathogenic variants in YWHAG.

ASXL3-related disorder: Molecular phenotyping and comprehensive review providing insights into disease mechanism.

ASXL3-related disorder, sometimes referred to as Bainbridge-Ropers syndrome, was first identified as a distinct neurodevelopmental disorder by Bainbridge et al. in 2013. Since then, there have been a number of case series and single case reports published worldwide.

HNRNPC haploinsufficiency affects alternative splicing of intellectual disability-associated genes and causes a neurodevelopmental disorder.

Heterogeneous nuclear ribonucleoprotein C (HNRNPC) is an essential, ubiquitously abundant protein involved in mRNA processing. Genetic variants in other members of the HNRNP family have been associated with neurodevelopmental disorders. Here, we describe 13 individuals with global developmental delay, intellectual disability, behavioral abnormalities, and subtle facial dysmorphology with heterozygous HNRNPC germline variants.

Germline pathogenic variants in HNRNPU are associated with alterations in blood methylome.

HNRNPU encodes a multifunctional RNA-binding protein that plays critical roles in regulating pre-mRNA splicing, mRNA stability, and translation. Aberrant expression and dysregulation of HNRNPU have been implicated in various human diseases, including cancers and neurological disorders. We applied a next generation sequencing based assay (EPIC-NGS) to investigate genome-wide methylation profiling for >2 M CpGs for 7 individuals with a neurodevelopmental disorder associated with HNRNPU germline pathogenic loss-of-function variants.

Expanding the phenotype of children presenting with hypoventilation with biallelic TBCK pathogenic variants and literature review.

Individuals with biallelic TBCK pathogenic variants present in infancy with distinctive facial features, profound hypotonia, severe intellectual impairment and epilepsy. Although rare, it may mimic other neurogenetic disorders leading to extensive investigations. Improved understanding of the clinical phenotype can support early monitoring of complications due to respiratory insufficiency.

EMILIN1 deficiency causes arterial tortuosity with osteopenia and connects impaired elastogenesis with defective collagen fibrillogenesis.

EMILIN1 (elastin-microfibril-interface-located-protein-1) is a structural component of the elastic fiber network and localizes to the interface between the fibrillin microfibril scaffold and the elastin core. How EMILIN1 contributes to connective tissue integrity is not fully understood. Here, we report bi-allelic EMILIN1 loss-of-function variants causative for an entity combining cutis laxa, arterial tortuosity, aneurysm formation, and bone fragility, resembling autosomal-recessive cutis laxa type 1B, due to EFEMP2 (FBLN4) deficiency.

Scope of professional roles for genetic counsellors and clinical geneticists in the United Kingdom : Position on behalf of the Association of Genetic Nurses and Counsellors and the Clinical Genetics Society.

This document is written on behalf of the two professional bodies in the United Kingdom that represent genetic counsellors (the Association of Genetic Nurses and Counsellors) and clinical geneticists (the Clinical Genetics Society) and aims to support multidisciplinary working of these professional groups highlighting within a quick-reference format, areas of shared practice and the distinctions between role profiles for a Consultant Clinical Geneticist, Principal/Consultant Genetic Counsellor and the new support role that we have termed 'Genomic Associate', see AGNC career structure [1]. This builds on published documents that articulate the scope of practice of the clinical genetics workforce [2] and specifically the genetic counsellor [3] and clinical geneticist [4] roles.

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.

Expanding the phenotype of TAB2 variants and literature review.

TAB2 is a gene located on chromosome 6q25.1 and plays a key role in development of the heart. Existing literature describes congenital heart disease as a common recognized phenotype of TAB2 gene variants, with evidence of a distinct syndromic phenotype also existing beyond this.

causing vascular malformations: the clinical and genetic differentiation of cutaneous venous malformations.

Cutaneous venous malformations frequently present with blue-pink lesions on the skin or mucosal surfaces. They can be problematic for patients who experience pain or unsightly lesions and can also be associated with significant bleeding. A proportion of venous malformations have been noted to occur in families, in particular glomuvenous malformations (GVMs).

Recommendations for whole genome sequencing in diagnostics for rare diseases.

In 2016, guidelines for diagnostic Next Generation Sequencing (NGS) have been published by EuroGentest in order to assist laboratories in the implementation and accreditation of NGS in a diagnostic setting. These guidelines mainly focused on Whole Exome Sequencing (WES) and targeted (gene panels) sequencing detecting small germline variants (Single Nucleotide Variants (SNVs) and insertions/deletions (indels)). Since then, Whole Genome Sequencing (WGS) has been increasingly introduced in the diagnosis of rare diseases as WGS allows the simultaneous detection of SNVs, Structural Variants (SVs) and other types of variants such as repeat expansions.

Uniparental disomy as a mechanism for X-linked chondrodysplasia punctata.

We describe a female infant with X-linked chondrodysplasia punctata (CDPX1) as a result of maternal isodisomy of the X chromosome. Targeted Sanger sequencing and targeted next-generation sequencing of ARSL were used to test for the familial variant. This patient was homozygous for ARSL NM_000047.