0000000000195120
AUTHOR
Frédéric Tran Mau-them
showing 17 related works from this author
A bi-allelic loss-of-function SARS1 variant in children with neurodevelopmental delay, deafness, cardiomyopathy, and decompensation during fever
2021
Aminoacyl-tRNA synthetases (aaRS) are ubiquitously expressed enzymes responsible for ligating amino acids to their cognate tRNA molecules through an aminoacylation reaction. The resulting aminoacyl-tRNA is delivered to ribosome elongation factors to participate in protein synthesis. Seryl-tRNA synthetase (SARS1) is one of the cytosolic aaRSs and catalyzes serine attachment to tRNASer . SARS1 deficiency has already been associated with moderate intellectual disability, ataxia, muscle weakness, and seizure in one family. We describe here a new clinical presentation including developmental delay, central deafness, cardiomyopathy, and metabolic decompensation during fever leading to death, in a…
Heterozygous HMGB1 loss-of-function variants are associated with developmental delay and microcephaly
2021
International audience; 13q12.3 microdeletion syndrome is a rare cause of syndromic intellectual disability. Identification and genetic characterization of patients with 13q12.3 microdeletion syndrome continues to expand the phenotypic spectrum associated with it. Previous studies identified four genes within the approximately 300 Kb minimal critical region including two candidate protein coding genes: KATNAL1 and HMGB1. To date, no patients carrying a sequence-level variant or a single gene deletion in HMGB1 or KATNAL1 have been described. Here we report six patients with loss-of-function variants involving HMGB1 and who had phenotypic features similar to the previously described 13q12.3 m…
Excess of de novo variants in genes involved in chromatin remodelling in patients with marfanoid habitus and intellectual disability.
2020
PurposeMarfanoid habitus (MH) combined with intellectual disability (ID) (MHID) is a clinically and genetically heterogeneous presentation. The combination of array CGH and targeted sequencing of genes responsible for Marfan or Lujan–Fryns syndrome explain no more than 20% of subjects.MethodsTo further decipher the genetic basis of MHID, we performed exome sequencing on a combination of trio-based (33 subjects) or single probands (31 subjects), of which 61 were sporadic.ResultsWe identified eight genes with de novo variants (DNVs) in at least two unrelated individuals (ARID1B, ATP1A1, DLG4, EHMT1, NFIX, NSD1, NUP205 and ZEB2). Using simulation models, we showed that five genes (DLG4, NFIX, …
High efficiency and clinical relevance of exome sequencing in the daily practice of neurogenetics
2021
ObjectiveTo assess the efficiency and relevance of clinical exome sequencing (cES) as a first-tier or second-tier test for the diagnosis of progressive neurological disorders in the daily practice of Neurology and Genetic Departments.MethodsSixty-seven probands with various progressive neurological disorders (cerebellar ataxias, neuromuscular disorders, spastic paraplegias, movement disorders and individuals with complex phenotypes labelled ‘other’) were recruited over a 4-year period regardless of their age, gender, familial history and clinical framework. Individuals could have had prior genetic tests as long as it was not cES. cES was performed in a proband-only (60/67) or trio (7/67) st…
Generation of an iPSC line (UNINAi001-A) from a girl with neonatal-onset epilepsy and non-syndromic intellectual disability carrying the homozygous K…
2021
Abstract Heterozygous variants in the KCNQ3 gene cause epileptic and/or developmental disorders of varying severity. Here we describe the generation of induced pluripotent stem cells (iPSCs) from a 9-year-old girl with pharmacodependent neonatal-onset epilepsy and intellectual disability who carry a homozygous single-base duplication in exon 12 of KCNQ3 (NM_004519.3: KCNQ3 c.1599dup; KCNQ3 p.PHE534ILEfs*15), and from a non-carrier brother of the proband. For iPSC generation, non-integrating episomal plasmid vectors were used to transfect fibroblasts isolated from skin biopsies. The obtained iPSC lines had a normal karyotype, showed embryonic stem cell-like morphology, expressed pluripotency…
Nucleocytoplasmic transport of the RNA-binding protein CELF2 regulates neural stem cell fates.
2020
The development of the cerebral cortex requires balanced expansion and differentiation of neural stem/progenitor cells (NPCs), which rely on precise regulation of gene expression. Because NPCs often exhibit transcriptional priming of cell-fate-determination genes, the ultimate output of these genes for fate decisions must be carefully controlled in a timely fashion at the post-transcriptional level, but how that is achieved is poorly understood. Here, we report that de novo missense variants in an RNA-binding protein CELF2 cause human cortical malformations and perturb NPC fate decisions in mice by disrupting CELF2 nucleocytoplasmic transport. In self-renewing NPCs, CELF2 resides in the cyt…
Clinical whole-exome sequencing for the diagnosis of rare disorders with congenital anomalies and/or intellectual disability: substantial interest of…
2017
International audience; PurposeCongenital anomalies and intellectual disability (CA/ID) are a major diagnostic challenge in medical genetics—50% of patients still have no molecular diagnosis after a long and stressful diagnostic “odyssey.” Solo clinical whole-exome sequencing (WES) was applied in our genetics center to improve diagnosis in patients with CA/ID.MethodsThis retrospective study examined 416 consecutive tests performed over 3 years to demonstrate the effectiveness of periodically reanalyzing WES data. The raw data from each nonpositive test was reanalyzed at 12 months with the most recent pipeline and in the light of new data in the literature. The results of the reanalysis for …
Hearing impairment as an early sign of alpha-mannosidosis in children with a mild phenotype: Report of seven new cases.
2019
Alpha-mannosidosis (AM) is a very rare (prevalence: 1/500000 births) autosomal recessive lysosomal storage disorder. It is characterized by multi-systemic involvement associated with progressive intellectual disability, hearing loss, skeletal anomalies, and coarse facial features. The spectrum is wide, from very severe and lethal to a milder phenotype that usually progresses slowly. AM is caused by a deficiency of lysosomal alpha-mannosidase. A diagnosis can be established by measuring the activity of lysosomal alpha-mannosidase in leucocytes and screening for abnormal urinary excretion of mannose-rich oligosaccharides. Genetic confirmation is obtained with the identification of MAN2B1 muta…
Haploinsufficiency of ARFGEF1 is associated with developmental delay, intellectual disability, and epilepsy with variable expressivity
2021
PURPOSE: ADP ribosylation factor guanine nucleotide exchange factors (ARFGEFs) are a family of proteins implicated in cellular trafficking between the Golgi apparatus and the plasma membrane through vesicle formation. Among them is ARFGEF1/BIG1, a protein involved in axon elongation, neurite development, and polarization processes. ARFGEF1 has been previously suggested as a candidate gene for different types of epilepsies, although its implication in human disease has not been well characterized.METHODS: International data sharing, in silico predictions, and in vitro assays with minigene study, western blot analyses, and RNA sequencing.RESULTS: We identified 13 individuals with heterozygous…
Further delineation of the female phenotype with KDM5C disease causing variants: 19 new individuals and review of the literature.
2020
X-linked intellectual disability (XLID) is a genetically heterogeneous condition involving more than 100 genes. To date, 35 pathogenic variants have been reported in the lysine specific demethylase 5C (KDM5C) gene. KDM5C variants are one of the major causes of moderate to severe XLID. Affected males present with short stature, distinctive facial features, behavioral disorders, epilepsy, and spasticity. For most of these variants, related female carriers have been reported, but phenotypic descriptions were poor. Here, we present clinical and molecular features of 19 females carrying 10 novel heterozygous variants affecting KDM5C function, including five probands with de novo variants. Four h…
High Rate of Recurrent De Novo Mutations in Developmental and Epileptic Encephalopathies
2017
Item does not contain fulltext Developmental and epileptic encephalopathy (DEE) is a group of conditions characterized by the co-occurrence of epilepsy and intellectual disability (ID), typically with developmental plateauing or regression associated with frequent epileptiform activity. The cause of DEE remains unknown in the majority of cases. We performed whole-genome sequencing (WGS) in 197 individuals with unexplained DEE and pharmaco-resistant seizures and in their unaffected parents. We focused our attention on de novo mutations (DNMs) and identified candidate genes containing such variants. We sought to identify additional subjects with DNMs in these genes by performing targeted sequ…
Genotype-first in a cohort of 95 fetuses with multiple congenital abnormalities: when exome sequencing reveals unexpected fetal phenotype-genotype co…
2020
PurposeMolecular diagnosis based on singleton exome sequencing (sES) is particularly challenging in fetuses with multiple congenital abnormalities (MCA). Indeed, some studies reveal a diagnostic yield of about 20%, far lower than in live birth individuals showing developmental abnormalities (30%), suggesting that standard analyses, based on the correlation between clinical hallmarks described in postnatal syndromic presentations and genotype, may underestimate the impact of the genetic variants identified in fetal analyses.MethodsWe performed sES in 95 fetuses with MCA. Blind to phenotype, we applied a genotype-first approach consisting of combined analyses based on variants annotation and …
Skraban‐Deardorff syndrome: Six new cases of WDR 26 ‐related disease and expansion of the clinical phenotype
2021
International audience; Skraban-Deardorff syndrome (a disease related to variations in the WDR26 gene; OMIM #617616) was first described in a cohort of 15 individuals in 2017. The syndrome comprises intellectual deficiency, severe speech impairment, ataxic gait, seizures, mild hypotonia with feeding difficulties during infancy, and dysmorphic features. Here, we report on six novel heterozygous de novo pathogenic variants in WDR26 in six probands. The patients’ phenotypes were consistent with original publication. One patient displayed marked hypotonia with an abnormal muscle biopsy; this finding warrants further investigation. Gait must be closely monitored, in order to highlight any muscul…
NEXMIF encephalopathy: an X-linked disorder with male and female phenotypic patterns
2021
Contains fulltext : 231688.pdf (Publisher’s version ) (Closed access) PURPOSE: Pathogenic variants in the X-linked gene NEXMIF (previously KIAA2022) are associated with intellectual disability (ID), autism spectrum disorder, and epilepsy. We aimed to delineate the female and male phenotypic spectrum of NEXMIF encephalopathy. METHODS: Through an international collaboration, we analyzed the phenotypes and genotypes of 87 patients with NEXMIF encephalopathy. RESULTS: Sixty-three females and 24 males (46 new patients) with NEXMIF encephalopathy were studied, with 30 novel variants. Phenotypic features included developmental delay/ID in 86/87 (99%), seizures in 71/86 (83%) and multiple comorbidi…
DLG4-related synaptopathy: a new rare brain disorder
2021
Contains fulltext : 245031.pdf (Publisher’s version ) (Closed access) PURPOSE: Postsynaptic density protein-95 (PSD-95), encoded by DLG4, regulates excitatory synaptic function in the brain. Here we present the clinical and genetic features of 53 patients (42 previously unpublished) with DLG4 variants. METHODS: The clinical and genetic information were collected through GeneMatcher collaboration. All the individuals were investigated by local clinicians and the gene variants were identified by clinical exome/genome sequencing. RESULTS: The clinical picture was predominated by early onset global developmental delay, intellectual disability, autism spectrum disorder, and attention deficit-hyp…
New insights into the clinical and molecular spectrum of the novel CYFIP2-related neurodevelopmental disorder and impairment of the WRC-mediated acti…
2021
International audience; Purpose: A few de novo missense variants in the cytoplasmic FMRP-interacting protein 2 (CYFIP2) gene have recently been described as a novel cause of severe intellectual disability, seizures, and hypotonia in 18 individuals, with p.Arg87 substitutions in the majority.Methods: We assembled data from 19 newly identified and all 18 previously published individuals with CYFIP2 variants. By structural modeling and investigation of WAVE-regulatory complex (WRC)-mediated actin polymerization in six patient fibroblast lines we assessed the impact of CYFIP2 variants on the WRC.Results: Sixteen of 19 individuals harbor two previously described and 11 novel (likely) disease-ass…
Am J Hum Genet
2019
ZMIZ1 is a coactivator of several transcription factors, including p53, the androgen receptor, and NOTCH1. Here, we report 19 subjects with intellectual disability and developmental delay carrying variants in ZMIZ1. The associated features include growth failure, feeding difficulties, microcephaly, facial dysmorphism, and various other congenital malformations. Of these 19, 14 unrelated subjects carried de novo heterozygous single-nucleotide variants (SNVs) or single-base insertions/deletions, 3 siblings harbored a heterozygous single-base insertion, and 2 subjects had a balanced translocation disrupting ZMIZ1 or involving a regulatory region of ZMIZ1. In total, we identified 13 point mutat…