Publications by authors named "Valence S"

Objective: To describe the MR features enabling prenatal diagnosis of pontocerebellar hypoplasia (PCH).

Method: This was a retrospective single monocentre study. The inclusion criteria were decreased cerebellar biometry on dedicated neurosonography and available fetal Magnetic Resonance Imaging (MRI) with PCH diagnosis later confirmed either genetically or clinically on post-natal MRI or by autopsy.

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  • - The Aristaless-related homeobox gene on the X chromosome is crucial for brain development, with well-documented disorders in males, but less clear effects in females, who are often asymptomatic.
  • - This study examined 10 unpublished female patients with new pathogenic variants and reviewed 63 previously documented cases, revealing a diverse clinical spectrum among females with these variants.
  • - Findings indicated that 42.5% of female carriers are asymptomatic, while 41% exhibit severe symptoms like intellectual disability or developmental conditions, with a higher prevalence of severe phenotypes in those with de novo variants compared to inherited ones.
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  • The study investigates anomalies of the corpus callosum (ACC), a common brain malformation, highlighting that the genetic causes of ACC without intellectual disability (ID) are not well understood.
  • Researchers identified a new dominant gene associated with ACC, reporting on nine individuals with a specific genetic variant linked to both familial inheritance and normal cognitive function.
  • Findings indicate that this gene may lead to ACC while maintaining normal intellectual abilities, suggesting a broader range of physical malformations associated with it beyond just eye conditions.
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By converting physical forces into electrical signals or triggering intracellular cascades, stretch-activated ion channels allow the cell to respond to osmotic and mechanical stress. Knowledge of the pathophysiological mechanisms underlying associations of stretch-activated ion channels with human disease is limited. Here, we describe 17 unrelated individuals with severe early-onset developmental and epileptic encephalopathy (DEE), intellectual disability, and severe motor and cortical visual impairment associated with progressive neurodegenerative brain changes carrying ten distinct heterozygous variants of TMEM63B, encoding for a highly conserved stretch-activated ion channel.

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BRAT1 biallelic variants are associated with rigidity and multifocal seizure syndrome, lethal neonatal (RMFSL), and neurodevelopmental disorder associating cerebellar atrophy with or without seizures syndrome (NEDCAS). To date, forty individuals have been reported in the literature. We collected clinical and molecular data from 57 additional cases allowing us to study a large cohort of 97 individuals and draw phenotype-genotype correlations.

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  • * Most variants of the SMARCC1 gene are loss of function (LoF) and typically passed down from unaffected parents, suggesting incomplete penetrance.
  • * This research presents the first antenatal cases of SMARCC1 LoF variants found through Whole Genome Sequencing, highlighting the challenges in diagnosis and genetic counseling due to its inheritance patterns.
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  • The study aimed to compare imaging and genetic findings in fetuses with corpus callosum abnormalities identified through prenatal exome sequencing (pES) between 2018 and 2020.
  • A total of 113 fetuses were included, revealing pathogenic/likely pathogenic (P/LP) genetic variants in certain types of abnormalities, with significant findings in cases with associated cerebellar issues.
  • The results indicated that P/LP variants were more common in non-isolated conditions and certain types of callosal dysgenesis, but no variants were found for isolated short CC, interhemispheric cysts, or pericallosal lipoma.
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Background And Purpose: Medullary tegmental cap dysplasia is a rare brainstem malformation, first described and defined by James Barkovich in his book from 2005 as an anomalous mass protruding from the posterior medullary surface. We describe the neuroimaging, clinical, postmortem, and genetic findings defining this unique malformation.

Materials And Methods: This is a multicenter, international, retrospective study.

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TRPM3 is a temperature- and neurosteroid-sensitive plasma membrane cation channel expressed in a variety of neuronal and non-neuronal cells. Recently, rare de novo variants in were identified in individuals with developmental and epileptic encephalopathy, but the link between TRPM3 activity and neuronal disease remains poorly understood. We previously reported that two disease-associated variants in TRPM3 lead to a gain of channel function .

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Objective: To report on a large cohort of fetuses with mild forms of tubulinopathy and to define prenatal ultrasound and magnetic resonance imaging (MRI) features that can facilitate prenatal diagnosis.

Methods: This was a retrospective multicenter study of fetuses diagnosed between January 2007 and February 2022 with a mild tubulinopathy (without lissencephaly or microlissencephaly). We collected and reviewed brain imaging and genetic data, and defined major criteria as findings observed in ≥ 70% of the patients and minor criteria as those observed in ≥ 50% but < 70% of the patients.

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Purpose: In this study, we describe the phenotype and genotype of the largest cohort of patients with Joubert syndrome (JS) carrying pathogenic variants on one of the most frequent causative genes, .

Methods: We selected 53 patients with pathogenic variants on , compiled and analysed their clinical, neuroimaging and genetic information and compared it to previous literature.

Results: Developmental delay (motor and language) was nearly constant but patients had normal intellectual efficiency in 74% of cases (20/27 patients) and 68% followed mainstream schooling despite learning difficulties.

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  • This study focuses on a rare prenatal diagnosis, specifically vermian cysts in fetuses, which had not been reported before.
  • Sixteen fetuses were included in the study, primarily female, with the cysts located in the vermian horizontal fissure, and all posterior fossa structures were found to be normal.
  • Postnatal outcomes for the majority were positive, with most children showing normal psychomotor development and no serious complications, although a few had minor developmental delays.
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Introduction: Brainstem disconnection syndrome is a rare and severe disease resulting from a midbrain-hindbrain segmental defect. Clinical signs include a severe neurological impairment, an early death (usually during the first year of life), and pathognomonic postnatal brain imaging features. Two major hypotheses are proposed to explain the etiopathogenesis of this syndrome, namely an inborn error of morphogenesis or a vascular disruption defect.

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Malignant pleural mesothelioma, a tumor arising from the membrane covering the lungs and the inner side of the ribs, is a cancer in which genetic alterations of genes encoding proteins that act on or are part of the Hippo-YAP1 signaling pathway are frequent. Dysfunctional Hippo signaling may result in aberrant activation of the transcriptional coactivator protein YAP1, which binds to and activates transcription factors of the TEAD family. Recent studies have associated elevated YAP1 protein activity with a poor prognosis of malignant mesothelioma and its resistance to current therapies, but its role in tumor maintenance is unclear.

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  • Pathogenic variants in the MYT1L gene lead to a neurodevelopmental disorder characterized by features like developmental delays, intellectual disabilities, and behavioral disorders.
  • A study analyzed genetic data from 40 previously unreported patients, adding to a total of 62 patients to better understand the clinical characteristics and genotype-phenotype correlations.
  • The research confirmed key phenotypic traits, introduced new clinical features, and emphasized that patients with certain genetic variants do not show distinct clinical differences, aiding in improved diagnosis and management of the disorder.
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De novo missense variants in encoding Kv10.1 are responsible for two clinically recognisable phenotypes: Temple-Baraitser syndrome (TBS) and Zimmermann-Laband syndrome (ZLS). The clinical overlap between these two syndromes suggests that they belong to a spectrum of -related encephalopathies.

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We report the case of a female patient aged 12 years referred to our pediatric sleep unit with a history of central sleep apnea associated with transient episodes of tachypnea on polysomnography recordings. The patient was otherwise healthy, with no personal or family medical history, and had a normal physical and neuropsychological examination. Brain magnetic resonance imaging showed signs of cerebellar vermis dysplasia but without the classical features of the molar tooth sign.

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  • The study examined the effectiveness of chromosomal microarray (CMA) and exome sequencing (ES) for diagnosing genetic causes in fetuses with abnormal corpus callosum (AbnCC), both isolated (iAbnCC) and nonisolated (niAbnCC).
  • Out of 65 fetuses tested, 23% had identifiable genetic variants associated with AbnCC and intellectual disabilities, providing crucial data for predicting developmental outcomes.
  • The findings emphasize the importance of genetic testing in guiding parents’ decisions about pregnancy outcomes and highlight the need for further research to refine counseling practices, especially following negative test results.
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Developmental and Epileptic encephalopathies (DEE) describe heterogeneous epilepsy syndromes, characterized by early-onset, refractory seizures and developmental delay (DD). Several DEE associated genes have been reported. With increased access to whole exome sequencing (WES), new candidate genes are being identified although there are fewer large cohort papers describing the clinical phenotype in such patients.

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Biallelic mutations in the PLCB1 gene, encoding for a phospholipase C beta isoform strongly expressed in the brain, have been reported to cause infantile epileptic encephalopathy in only four children to date. We report here three additional patients to delineate the phenotypic and genotypic characteristics of the disease. Our three patients were one sporadic case with an intragenic homozygous deletion and two cousins with the homozygous p.

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AMPA receptors (AMPARs) are tetrameric ligand-gated channels made up of combinations of GluA1-4 subunits encoded by GRIA1-4 genes. GluA2 has an especially important role because, following post-transcriptional editing at the Q607 site, it renders heteromultimeric AMPARs Ca-impermeable, with a linear relationship between current and trans-membrane voltage. Here, we report heterozygous de novo GRIA2 mutations in 28 unrelated patients with intellectual disability (ID) and neurodevelopmental abnormalities including autism spectrum disorder (ASD), Rett syndrome-like features, and seizures or developmental epileptic encephalopathy (DEE).

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Ataxia-telangiectasia-like disorder (ATLD) is a rare genomic instability syndrome caused by biallelic variants of MRE11 (meiotic recombination 11) characterized by progressive cerebellar ataxia and typical karyotype abnormalities. These symptoms are common to those of ataxia-telangiectasia, which is consistent with the key role of MRE11 in ataxia-telangiectasia mutated (ATM) activation after DNA double-strand breaks. Three unrelated French patients were referred with ataxia.

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Objective: Vascular prostheses for small caliber bypass grafts in cardiac and vascular diseases or for access surgery are still missing. Poly (Ɛ-caprolactone) (PCL) has been previously investigated by our group and showed good biocompatibility and mechanical properties in vitro and rapid endothelialisation, cellular infiltration and vascularisation in vivo yielding optimal patency in the abdominal aortic position. The aim of the present study is to evaluate our PCL graft in the carotid position and to compare its outcome to the grafts implanted in the abdominal aortic position.

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  • A study investigated balanced chromosomal rearrangements in patients with intellectual disabilities and congenital anomalies using next-generation sequencing to identify breakpoints at a molecular level.
  • The research characterized breakpoints in 55 patients, revealing that 89% of chromosomal rearrangements were detected, with non-homologous end-joining identified as the primary repair mechanism.
  • The study found that a diagnosis could be established in about 44.8% of patients, revealing disruptions in genes and suggesting that paired-end whole genome sequencing is effective for clinical applications in structural variation analysis.
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