Publications by authors named "Labalme A"

Generation 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).

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  • * The study focused on an Italian family with four affected members (the mother and three siblings) who exhibited myotonia, along with two of them having JME; genetic testing revealed a shared variant in the SCN4A gene among those affected.
  • * Findings suggest that the myotonia and epilepsy in this family may stem from the same genetic mutation in the SCN4A gene, indicating that
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Background And Objectives: Heterozygous variants in RAR-related orphan receptor B () have recently been associated with susceptibility to idiopathic generalized epilepsy. However, few reports have been published so far describing pathogenic variants of this gene in patients with epilepsy and intellectual disability (ID). In this study, we aimed to delineate the epilepsy phenotype associated with pathogenic variants and to provide arguments in favor of the pathogenicity of variants.

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  • Developmental and epileptic encephalopathies (DEEs) are severe conditions marked by both seizures and developmental delays, often linked to genetic causes that are increasingly identified through advanced sequencing technologies.
  • A specific pathogenic variant in the GRM7 gene, responsible for encoding a certain receptor in the brain, has been identified as a cause of a severe DEE, typically inherited in an autosomal recessive manner.
  • This report presents five patients from three families with mutations in the GRM7 gene, contributing to the literature on this rare syndrome and helping to clarify the relationship between genetic variation and clinical outcomes.
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Objective: N-methyl-d-aspartate (NMDA) receptors are expressed at synaptic sites, where they mediate fast excitatory neurotransmission. NMDA receptors are critical to brain development and cognitive function. Natural variants to the GRIN1 gene, which encodes the obligatory GluN1 subunit of the NMDA receptor, are associated with severe neurological disorders that include epilepsy, intellectual disability, and developmental delay.

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Sexual development is a complex process relying on numerous genes. Disruptions in some of these genes are known to cause differences of sexual development (DSDs). Advances in genome sequencing allowed the discovery of new genes implicated in sexual development, such as PBX1.

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  • The study investigates the role of KCNQ5 gene variants in genetic generalized epilepsy (GGE) and their link to developmental issues.
  • Researchers analyzed genetic data from 1292 families and found several harmful variants associated with GGE and some intellectual disabilities.
  • The identified variants lead to a loss-of-function effect in the K7.5 potassium channels, reducing the M-current and possibly increasing neuron excitability, which may contribute to the seizures observed in affected individuals.
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Pathogenic variants in KCNQ2 encoding for Kv7.2 potassium channel subunits have been found in patients affected by widely diverging epileptic phenotypes, ranging from Self-Limiting Familial Neonatal Epilepsy (SLFNE) to severe Developmental and Epileptic Encephalopathy (DEE). Thus, understanding the pathogenic molecular mechanisms of KCNQ2 variants and their correlation with clinical phenotypes has a relevant impact on the clinical management of these patients.

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  • DNASE1L3 is an enzyme linked to the breakdown of chromatin from dying cells and is associated with lupus, but its role in interferon signaling in humans is not fully understood.
  • In this study, researchers analyzed five new patients with rare DNASE1L3 mutations, finding that they exhibited a temporary increase in interferon-stimulated genes during disease activity.
  • The findings underscore the severity of DNASE1L3 deficiencies, which often lead to conditions like lupus nephritis and other serious symptoms, with additional patients reviewed revealing a general trend of poor outcomes.
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Developmental and epileptic encephalopathies (DEEs) are neurodevelopmental diseases characterized by refractory epilepsy, distinct electroencephalographic and neuroradiological features, and various degrees of developmental delay. Mutations in KCNQ2, KCNQ3, and, more rarely, KCNQ5 genes encoding voltage-gated potassium channel subunits variably contributing to excitability control of specific neuronal populations at distinct developmental stages have been associated to DEEs. In the present work, the clinical features of two DEE patients carrying de novo KCNQ5 variants affecting the same residue in the pore region of the Kv7.

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  • The EPIGENE network, formed in 2014 by a group of specialists in genetics and neurology, aims to enhance the diagnosis of Mendelian epileptic disorders in France through advanced sequencing techniques.
  • Since its creation, the network has expanded to include more centers, resulting in the development of a multigene panel that has grown from 68 to 144 genes, with a significant diagnostic success rate of 31% from over 4,000 analyzed cases.
  • Looking ahead, the network plans to offer whole-genome sequencing for young patients with severe epilepsy as part of the upcoming 2025 French Genomic Medicine Plan, fostering collaborations with the rare epilepsies reference center.
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We report the screening of a large panel of genes in a series of 100 fetuses (98 families) affected with severe renal defects. Causative variants were identified in 22% of cases, greatly improving genetic counseling. The percentage of variants explaining the phenotype was different according to the type of phenotype.

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  • F8 duplications, found on the X chromosome, can lead to various clinical outcomes, ranging from benign conditions to severe hemophilia A symptoms, depending on their location.
  • The study aimed to analyze two significant duplications found in patients with severe intellectual disabilities but no bleeding disorders, using whole genome sequencing for detailed characterization.
  • Results revealed complex genomic rearrangements in both patients, preserving an intact F8 gene, emphasizing the importance of using advanced genomic analysis to understand their genetic variations and improve genetic counseling.
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De novo heterozygous missense mutations in TRPM3 have been shown to cause developmental and epileptic encephalopathies (DEE). It is a very rare condition, as only 9 patients have been described to date. We report here a novel patient carrying the recurrent p.

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Male infertility affects about 7% of the general male population. Balanced structural chromosomal rearrangements are observed in 0.4-1.

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Purpose: We describe a novel neurobehavioral phenotype of autism spectrum disorder (ASD), intellectual disability, and/or attention-deficit/hyperactivity disorder (ADHD) associated with de novo or inherited deleterious variants in members of the RFX family of genes. RFX genes are evolutionarily conserved transcription factors that act as master regulators of central nervous system development and ciliogenesis.

Methods: We assembled a cohort of 38 individuals (from 33 unrelated families) with de novo variants in RFX3, RFX4, and RFX7.

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  • NCKAP1/NAP1 is crucial for neuronal development and impacts cytoskeletal dynamics in the brain; disruptions can lead to conditions like autism spectrum disorder (ASD) and intellectual disability.
  • This research analyzes genetic data from 21 individuals with harmful NCKAP1 variants, reporting a correlation with neurodevelopmental disorders such as ASD, language delays, and motor skill issues.
  • Findings indicate that NCKAP1 is highly expressed in brain development stages, particularly in excitatory neurons, and its loss-of-function may hinder neuronal migration, linking it to ASD and associated delays.
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  • Researchers performed exome sequencing on two unrelated families with progressive myoclonus epilepsy and discovered a rare variant affecting the SLC7A6OS gene in both families.
  • The analysis showed that this genetic change caused splice site issues, leading to abnormal protein expression linked to the condition.
  • Haplotype analysis indicated a common ancestor between the families, supporting the idea that loss-of-function variants in SLC7A6OS could be a new genetic cause of this type of epilepsy.
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De novo variants in KCNQ2 encoding for Kv7.2 voltage-dependent neuronal potassium (K) channel subunits are associated with developmental epileptic encephalopathy (DEE). We herein describe the clinical and electroencephalographic (EEG) features of a child with early-onset DEE caused by the novel KCNQ2 p.

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PIGC (OMIM 601730) encodes the PIGC protein, which is part of an enzyme complex involved in the biosynthesis of the glycosylphosphatidylinositol protein anchor. The other proteins in the complex include PIGA, PIGH, PIGQ, PIGY, PIGP and DPM2. Homozygous and compound heterozygous mutations in PIGC have recently been described to cause severe global developmental delay, intellectual disability, and seizures in two unrelated families, without indication of another system involvement or dysmorphism.

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Objective: Self-limited focal epilepsies of childhood (SFEC) are amongst the best defined and most frequent epilepsy syndromes affecting children with usually normal developmental milestones. They include core syndromes such as Rolandic epilepsy or "Benign" epilepsy with Centro-Temporal Spikes and the benign occipital epilepsies, the early onset Panayiotopoulos syndrome and the late-onset Gastaut type. Atypical forms exist for all of them.

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PITX1 is a homeobox transcription factor essential for hindlimb morphogenesis. Two PITX1-related human disorders have been reported to date: PITX1 ectopic expression causes Liebenberg syndrome, characterized by malformation of upper limbs showing a "lower limb" appearance; PITX1 deletions or missense variation cause a syndromic picture including clubfoot, tibial hemimelia, and preaxial polydactyly. We report two novel PITX1 missense variants, altering PITX1 transactivation ability, in three individuals from two unrelated families showing a distinct recognizable autosomal dominant syndrome, including first branchial arch, pelvic, patellar, and male genital abnormalities.

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Epilepsy of infancy with migrating focal seizures (EIMFS) is now a well-recognized early-onset syndrome included in the ILAE classification of the epilepsies. KCNT1 gain-of-function variants are identified in about half of patients. In the remaining cases, the underlying genetic component is far more heterogeneous with sporadic mutations occasionally reported in SCN1A, SCN2A, SLC12A5, TBC1D24, PLCB1, SLC25A22, and KCNQ2.

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Purpose: Somatic variants in tumor necrosis factor receptor-associated factor 7 (TRAF7) cause meningioma, while germline variants have recently been identified in seven patients with developmental delay and cardiac, facial, and digital anomalies. We aimed to define the clinical and mutational spectrum associated with TRAF7 germline variants in a large series of patients, and to determine the molecular effects of the variants through transcriptomic analysis of patient fibroblasts.

Methods: We performed exome, targeted capture, and Sanger sequencing of patients with undiagnosed developmental disorders, in multiple independent diagnostic or research centers.

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