Publications by authors named "Mouna Barat-Houari"

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.

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Purpose: BCL11B-related disorder (BCL11B-RD) arises from rare genetic variants within the BCL11B gene, resulting in a distinctive clinical spectrum encompassing syndromic neurodevelopmental disorder, with or without intellectual disability, associated with facial features and impaired immune function. This study presents an in-depth clinico-biological analysis of 20 newly reported individuals with BCL11B-RD, coupled with a characterization of genome-wide DNA methylation patterns of this genetic condition.

Methods: Through an international collaboration, clinical and molecular data from 20 individuals were systematically gathered, and a comparative analysis was conducted between this series and existing literature.

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Autosomal recessive primary microcephaly type 3 (MCPH3) caused by pathogenic variations in CDK5RAP2, is characterized by sensorineural hearing loss, abnormality of skin pigmentation, ocular defects and severe microcephaly associated with neurodevelopmental delay. In this study, we expand the phenotype of MCPH3 as we describe a 10-year-old girl with a biallelic exonic frameshift variant in CDK5RAP2 displaying previously unreported features usually associated with Meier-Gorlin and microcephalic osteodysplastic primordial dwarfism type II (MOPDII). We further describe the clinical phenotype of this form of centrosomal-based primary microcephaly and emphasize the importance of skeletal defect screening in affected individuals.

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Article Synopsis
  • The study focuses on "episignatures," which are unique DNA methylation patterns used as biomarkers for diagnosing various genetic syndromes, particularly neurodevelopmental disorders.
  • Researchers analyzed DNA methylation changes in 65 genetic syndromes, identifying specific differentially methylated probes (DMPs) and regions (DMRs) associated with these conditions.
  • Findings indicated that DMPs and DMRs were mostly located in gene promoters and pathways related to neurodevelopment, highlighting a connection between gene mutations and altered DNA methylation profiles in these disorders.
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Purpose: Although haploinsufficiency of ANKRD11 is among the most common genetic causes of neurodevelopmental disorders, the role of rare ANKRD11 missense variation remains unclear. We characterized clinical, molecular, and functional spectra of ANKRD11 missense variants.

Methods: We collected clinical information of individuals with ANKRD11 missense variants and evaluated phenotypic fit to KBG syndrome.

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  • - This study focused on 15 infants under a year old in intensive care who were suspected to have genetic conditions and underwent rapid trio exome sequencing (rES) from April 2019 to April 2021.
  • - The key finding was that results from rES were available to parents within 16 days for 86% of the participants, and 40% received a confirmed diagnosis.
  • - The study highlights the potential of rES to enhance medical care for critically ill infants, despite some patients not receiving a diagnosis and a few passing away before results were available.
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  • Rare genetic variants in the CDK13 gene cause CDK13-related disorder (CDK13-RD), which includes symptoms like developmental delays, facial abnormalities, and seizures; this paper presents 18 new cases with detailed disease characterization.
  • The study involved clinical data analysis, comparison of DNA methylation between CDK13-RD individuals and controls, and the development of a machine learning model to differentiate CDK13-RD from other disorders.
  • The findings reveal new symptoms associated with CDK13-RD, establish a specific DNA methylation profile as a diagnostic tool, and highlight similarities with another disorder related to the CCNK gene.
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Overlapping clinical phenotypes and an expanding breadth and complexity of genomic associations are a growing challenge in the diagnosis and clinical management of Mendelian disorders. The functional consequences and clinical impacts of genomic variation may involve unique, disorder-specific, genomic DNA methylation episignatures. In this study, we describe 19 novel episignature disorders and compare the findings alongside 38 previously established episignatures for a total of 57 episignatures associated with 65 genetic syndromes.

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Purpose: Gabriele-de Vries syndrome (GADEVS) is a rare genetic disorder characterized by developmental delay and/or intellectual disability, hypotonia, feeding difficulties, and distinct facial features. To refine the phenotype and to better understand the molecular basis of the syndrome, we analyzed clinical data and performed genome-wide DNA methylation analysis of a series of individuals carrying a YY1 variant.

Methods: Clinical data were collected for 13 individuals not yet reported through an international call for collaboration.

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  • Kabuki syndrome (KS) is a rare genetic disorder linked to mutations in the KMT2D and KDM6A genes, causing two types: KS1 and KS2.
  • The study aimed to identify differences in facial morphology between KS1 and KS2 using a facial-recognition algorithm, comparing images of individuals from a specific ethnicity.
  • Results showed a statistically significant difference in facial characteristics between the two types, validated by trained clinical geneticists, highlighting the algorithm's effectiveness in distinguishing KS1 and KS2.
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  • Osteoarthritis (OA) is a common joint disease, and this study focuses on early-onset OA, which affects people younger than the typical age range; it examines the genetic causes specifically in individuals with nonsyndromic early-onset OA.
  • The study involved 45 patients with specific criteria, and researchers used genetic sequencing to identify variants in some patients, notably the COL2A1 gene, which was found in the majority of those with a genetic cause for their condition.
  • The findings suggest that COL2A1 is the primary genetic factor for nonsyndromic early-onset OA, and highlight the need for genetic testing in patients needing joint replacements before age 45, along with lifestyle recommendations for prevention.
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Genetic syndromes frequently present with overlapping clinical features and inconclusive or ambiguous genetic findings which can confound accurate diagnosis and clinical management. An expanding number of genetic syndromes have been shown to have unique genomic DNA methylation patterns (called "episignatures"). Peripheral blood episignatures can be used for diagnostic testing as well as for the interpretation of ambiguous genetic test results.

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Kabuki syndrome (KS, KS1: OMIM 147920 and KS2: OMIM 300867) is caused by pathogenic variations in KMT2D or KDM6A. KS is characterized by multiple congenital anomalies and neurodevelopmental disorders. Growth restriction is frequently reported.

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Unlabelled: PurposeBased on prenatal suspicion of the combination of radioulnar or radiohumeral synostosis and a peculiar shape of the skull suggestive of craniosynostosis, we report on six patients from four unrelated consanguineous families in whom Antley-Bixler syndrome was suspected during the prenatal period without mutation in genes known to be associated with the syndrome.MethodsMolecular diagnosis involved whole-exome and gene-panel sequencing.

Results: All sequenced patients showed a unique homozygous mutation of c.

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Kabuki syndrome (KS) is a rare but recognizable condition that consists of a characteristic face, short stature, various organ malformations, and a variable degree of intellectual disability. Mutations in KMT2D have been identified as the main cause for KS, whereas mutations in KDM6A are a much less frequent cause. Here, we report a mutation screening in a case series of 347 unpublished patients, in which we identified 12 novel KDM6A mutations (KS type 2) and 208 mutations in KMT2D (KS type 1), 132 of them novel.

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Heterozygous COL2A1 variants cause a wide spectrum of skeletal dysplasia termed type II collagenopathies. We assessed the impact of this gene in our French series. A decision tree was applied to select 136 probands (71 Stickler cases, 21 Spondyloepiphyseal dysplasia congenita cases, 11 Kniest dysplasia cases, and 34 other dysplasia cases) before molecular diagnosis by Sanger sequencing.

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Mutations in the COL2A1 gene cause a spectrum of rare autosomal-dominant conditions characterized by skeletal dysplasia, short stature, and sensorial defects. An early diagnosis is critical to providing relevant patient care and follow-up, and genetic counseling to affected families. There are no recent exhaustive descriptions of the causal mutations in the literature.

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Background. Venous malformations (VM) result from an error in vascular morphogenesis. The first gene suspected in their development is the TEK gene (tyrosine kinase, endothelial).

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Dysspondyloenchondromatosis is a rare form of generalized enchondromatosis associated with spinal involvement. This skeletal dysplasia is characterized by multiple enchondromas present in vertebrae as well as in metaphyseal and diaphyseal parts of the long tubular bones, post-natal short stature, and early development of kyphoscoliosis. A novel heterozygous missense mutation in COL2A1 was recently identified in a patient with dysspondyloenchondromatosis.

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Objective: We have conducted the first study of the association of interleukin (IL)-10, tumor necrosis factor alpha (TNF-α), and IL23R-IL12RB2 region single nucleotide polymorphisms (SNPs) with Behçet's disease (BD) in Western Algeria.

Methods: A total of 51 BD patients and 96 unrelated controls from West region of Algeria were genotyped by direct sequencing for 11 SNPs including 2 SNPs from the IL10 promoter [c.-819T > C (rs1800871), c.

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