Intellectual Developmental Disorder with Dysmorphic Facies and Ptosis (IDDDFP) is a rare autosomal dominant syndrome caused by pathogenic variants in the BRPF1 gene, which is critical for chromatin regulation. This study expands the clinical and molecular spectrum of IDDDFP by analysing 29 new patients from 20 families with confirmed BRPF1 variants. Our cohort presented with a wide range of clinical features including developmental delay, intellectual disability (ID) and characteristic dysmorphic facial features such as ptosis, blepharophimosis and a broad nasal bridge.
View Article and Find Full Text PDFPathogenic variants are associated with neonatal epilepsies, ranging from self-limited neonatal epilepsy to -developmental and epileptic encephalopathy (DEE). In this study, next-generation sequencing was performed, applying a panel of 142 epilepsy genes on three unrelated individuals and affected family members, showing a wide variability in the epileptic spectrum. The genetic analysis revealed two likely pathogenic missense variants (c.
View Article and Find Full Text PDFThe Houge type of X-linked syndromic intellectual developmental disorder (MRXSHG) encompasses a spectrum of neurodevelopmental disorders characterized by intellectual disability (ID), language/speech delay, attention issues, and epilepsy. These conditions arise from hemizygous or heterozygous deletions, along with point mutations, affecting CNKSR2, a gene located at Xp22.12.
View Article and Find Full Text PDFRetinoblastoma (RB) proteins are highly conserved transcriptional regulators that play important roles during development by regulating cell-cycle gene expression. RBL2 dysfunction has been linked to a severe neurodevelopmental disorder. However, to date, clinical features have only been described in six individuals carrying five biallelic predicted loss of function (pLOF) variants.
View Article and Find Full Text PDFRecent discoveries have revealed that genetic variants in γ-aminobutyric acid type A (GABA) receptor subunits can lead to both gain-of-function (GOF) and loss-of-function (LOF) receptors. GABA receptors, however, have a pseudosymmetrical pentameric assembly, and curiously diverse functional outcomes have been reported for certain homologous variants in paralogous genes (paralogous variants). To investigate this, we assembled a cohort of 11 individuals harboring paralogous M1 proline missense variants in , , and Seven mutations (α1, α1, β2, β3, β3, γ2, and γ2) in α1β2/3γ2 receptors were analyzed using electrophysiological examinations and molecular dynamics simulations.
View Article and Find Full Text PDFPurpose: 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 analysed detailed clinical and genetic data for all individuals.
Objective: There is currently scarce data on the electroclinical characteristics of epilepsy associated with synapsin 1 (SYN1) pathogenic variations. We examined clinical and electro-encephalographic (EEG) features in patients with epilepsy and SYN1 variants, with the aim of identifying a distinctive electroclinical pattern.
Methods: In this retrospective multicenter study, we collected and reviewed demographic, genetic, and epilepsy data of 19 male patients with SYN1 variants.
Purpose: Valproic acid or valproate is an effective antiepileptic drug; however, embryonic exposure to valproate can result in a teratogenic disorder referred to as fetal valproate syndrome (OMIM #609442). Currently there are no diagnostic biomarkers for the condition. This study aims to define an episignature biomarker for teratogenic antenatal exposure to valproate.
View Article and Find Full Text PDFObjectives: To present a case series of novel variants in patients presenting with genetic epileptic and developmental encephalopathy.
Background: CHD2 gene encodes an ATP-dependent enzyme, chromodomain helicase DNA-binding protein 2, involved in chromatin remodeling. Pathogenic variants in CHD2 are linked to early-onset conditions such as developmental and epileptic encephalopathy, drug-resistant epilepsies, and neurodevelopmental disorders.
Objective: DYNC1H1 variants are involved on a disease spectrum from neuromuscular disorders to neurodevelopmental disorders. DYNC1H1-related epilepsy has been reported in small cohorts. We dissect the electroclinical features of 34 patients harboring de novo DYNC1H1 pathogenic variants, identify subphenotypes on the DYNC1H1-related epilepsy spectrum, and compare the genotype-phenotype correlations observed in our cohort with the literature.
View Article and Find Full Text PDFGeneration and subsequently accessibility of secondary findings (SF) in diagnostic practice is a subject of debate around the world and particularly in Europe. The French FIND study has been set up to assess patient/parent expectations regarding SF from exome sequencing (ES) and to collect their real-life experience until 1 year after the delivery of results. 340 patients who had ES for undiagnosed developmental disorders were included in this multicenter mixed study (quantitative N = 340; qualitative N = 26).
View Article and Find Full Text PDFObjective: The increasingly rapid pace of advancement in genetic testing may lead to inequalities in technical and human resources with a negative impact on optimal epilepsy clinical practice. In this view, the European Reference Network (ERN) for Rare and Complex Epilepsies EpiCARE conducted a survey addressing several aspects of accessibility, availability, costs, and standard practices on genetic testing across ERN EpiCARE centers.
Methods: An online Google form was sent to 70 representatives of ERN EpiCARE centers.
Objectives: -related disorders encompass heterogeneous neuropsychiatric manifestations through GABAergic dysregulation, without any specific abnormalities on brain MRI, nor evidence of dopaminergic cell loss on I-FP-β-CIT SPECT. We report here a case of globus pallidus lesions and dopaminergic denervation in a patient with a pathogenic variant.
Methods: A 26-year-old female patient with intellectual disability, behavioral, and psychiatric disorders treated by neuroleptics for many years developed a parkinsonian syndrome associated with mild hand dystonia and chorea.
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.