This study aims to describe the ophthalmic characteristics of autosomal dominant (AD) WFS1-associated optic atrophy (AD WFS1-OA), and to explore phenotypic differences with dominant optic atrophy (DOA) caused by mutations in the OPA1-gene. WFS1-associated diseases, or 'wolframinopathies', exhibit a spectrum of ocular and systemic phenotypes, of which the autosomal recessive Wolfram syndrome has been the most extensively studied. AD mutations in WFS1 also cause various phenotypical changes including OA.
View Article and Find Full Text PDFCraniosynostosis may present in isolation, 'non-syndromic', or with additional congenital anomalies/neurodevelopmental disorders, 'syndromic'. Clinical focus shifted from confirming classical syndromic cases to offering genetic testing to all craniosynostosis patients. This retrospective study assesses diagnostic yield of molecular testing by investigating prevalences of chromosomal and monogenic (likely) pathogenic variants in an 11-year cohort of 1020 craniosynostosis patients.
View Article and Find Full Text PDFIndividuals with autism spectrum disorder (ASD) exhibit an increased burden of de novo mutations (DNMs) in a broadening range of genes. While these studies have implicated hundreds of genes in ASD pathogenesis, which DNMs cause functional consequences in vivo remains unclear. We functionally test the effects of ASD missense DNMs using Drosophila through "humanization" rescue and overexpression-based strategies.
View Article and Find Full Text PDFCongenital diaphragmatic hernia (CDH) is a life-threatening birth defect that presents as either an isolated diaphragm defect or as part of a complex disorder with a wide array of anomalies (complex CDH). Some patients with complex CDH display distinct craniofacial anomalies such as craniofrontonasal dysplasia or craniosynostosis, defined by the premature closure of cranial sutures. Using clinical whole exome sequencing (WES), we found a missense variant in a patient with a left-sided congenital diaphragmatic hernia as well as sagittal suture craniosynostosis.
View Article and Find Full Text PDFInt J Pediatr Otorhinolaryngol
January 2022
Objectives: In patients with mandibular hypoplasia, mandibular distraction osteogenesis (MDO) aims to relieve tongue-based airway obstruction. Drug-induced sleep endoscopy (DISE) provides a dynamic assessment of the upper airway and visualizes anatomical site and cause of airway obstruction. The aim of this study was to evaluate the effect of MDO on tongue-based airway obstruction found by DISE within a non-isolated patient population with severe upper airway obstruction (UAO).
View Article and Find Full Text PDFKDM4B is a lysine-specific demethylase with a preferential activity on H3K9 tri/di-methylation (H3K9me3/2)-modified histones. H3K9 tri/di-demethylation is an important epigenetic mechanism responsible for silencing of gene expression in animal development and cancer. However, the role of KDM4B on human development is still poorly characterized.
View Article and Find Full Text PDFObjective: We aimed to delineate the phenotypic spectrum and long-term outcome of individuals with KCNB1 encephalopathy.
Methods: We collected genetic, clinical, electroencephalographic, and imaging data of individuals with KCNB1 pathogenic variants recruited through an international collaboration, with the support of the family association "KCNB1 France." Patients were classified as having developmental and epileptic encephalopathy (DEE) or developmental encephalopathy (DE).
Aim: To assess the long-term outcomes of our management protocol for Saethre-Chotzen syndrome, which includes one-stage fronto-orbital advancement.
Method: All patients born with Saethre-Chotzen syndrome between January 1992 and March 2017 were included. Evaluated parameters included occipital frontal head circumference (OFC), fundoscopy, neuroimaging (ventricular size, tonsillar position, and the presence of collaterals/an abnormal transverse sinus), polysomnography, and ophthalmological outcomes.
Rapid developments in genome technology and a growing interest in personalized healthcare have led to a large rise in the range and use of commercial DNA tests, the so-called direct-to-consumer genetic tests (DTC-GT). DTC-GT can be of a non-medical (e.g.
View Article and Find Full Text PDFPurpose: To delineate the genotype-phenotype correlation in individuals with likely pathogenic variants in the CLTC gene.
Methods: We describe 13 individuals with de novo CLTC variants. Causality of variants was determined by using the tolerance landscape of CLTC and computer-assisted molecular modeling where applicable.
SATB2-associated syndrome (SAS) is an autosomal dominant neurodevelopmental disorder caused by alterations in the SATB2 gene. Here we present a review of published pathogenic variants in the SATB2 gene to date and report 38 novel alterations found in 57 additional previously unreported individuals. Overall, we present a compilation of 120 unique variants identified in 155 unrelated families ranging from single nucleotide coding variants to genomic rearrangements distributed throughout the entire coding region of SATB2.
View Article and Find Full Text PDFThe Mediator is an evolutionarily conserved, multi-subunit complex that regulates multiple steps of transcription. Mediator activity is regulated by the reversible association of a four-subunit module comprising CDK8 or CDK19 kinases, together with cyclin C, MED12 or MED12L, and MED13 or MED13L. Mutations in MED12, MED13, and MED13L were previously identified in syndromic developmental disorders with overlapping phenotypes.
View Article and Find Full Text PDFGermline mutations in succinate dehydrogenase subunit B and D ( and ) are predisposed to hereditary paraganglioma (PGL) and pheochromocytoma (PHEO). The phenotype of pathogenic variants varies according to the causative gene. In this retrospective study, we estimate the mortality of a nationwide cohort of variant carriers and that of a large cohort of variant carriers and compare it to the mortality of a matched cohort of the general Dutch population.
View Article and Find Full Text PDFNext-generation sequencing is a powerful tool for the discovery of genes related to neurodevelopmental disorders (NDDs). Here, we report the identification of a distinct syndrome due to de novo or inherited heterozygous mutations in Tousled-like kinase 2 (TLK2) in 38 unrelated individuals and two affected mothers, using whole-exome and whole-genome sequencing technologies, matchmaker databases, and international collaborations. Affected individuals had a consistent phenotype, characterized by mild-borderline neurodevelopmental delay (86%), behavioral disorders (68%), severe gastro-intestinal problems (63%), and facial dysmorphism including blepharophimosis (82%), telecanthus (74%), prominent nasal bridge (68%), broad nasal tip (66%), thin vermilion of the upper lip (62%), and upslanting palpebral fissures (55%).
View Article and Find Full Text PDFUnraveling the causes and pathomechanisms of progressive disorders is essential for the development of therapeutic strategies. Here, we identified heterozygous pathogenic missense variants of LMX1A in two families of Dutch origin with progressive nonsyndromic hearing impairment (HI), using whole exome sequencing. One variant, c.
View Article and Find Full Text PDFBurn-McKeown syndrome (BMKS) is a rare syndrome characterized by choanal atresia, prominent ears, abnormalities of the outer third of the lower eyelid, structural cardiac abnormalities, conductive and sensorineural hearing loss, and cleft lip. Recently, causative compound heterozygous variants were identified in TXNL4A. We analyzed an individual with clinical features of BMKS and her parents by whole-genome sequencing and identified compound heterozygous variants in TXNL4A (a novel splice site variant (c.
View Article and Find Full Text PDFObjective: Succinate dehydrogenase B subunit () gene germline mutations predispose to pheochromocytomas, sympathetic paragangliomas, head and neck paragangliomas and non-paraganglionic tumors (e.g. renal cell carcinoma, gastrointestinal stromal tumor and pituitary neoplasia).
View Article and Find Full Text PDFHearing impairment (HI) is genetically heterogeneous which hampers genetic counseling and molecular diagnosis. Testing of several single HI-related genes is laborious and expensive. In this study, we evaluate the diagnostic utility of whole-exome sequencing (WES) targeting a panel of HI-related genes.
View Article and Find Full Text PDFTCF12-related craniosynostosis can be caused by small heterozygous loss-of-function mutations in TCF12. Large intragenic rearrangements, however, have not been described yet. Here, we present the identification of four large rearrangements in TCF12 causing TCF12-related craniosynostosis.
View Article and Find Full Text PDFDespite developments in targeted gene sequencing and whole-genome analysis techniques, the robust detection of all genetic variation, including structural variants, in and around genes of interest and in an allele-specific manner remains a challenge. Here we present targeted locus amplification (TLA), a strategy to selectively amplify and sequence entire genes on the basis of the crosslinking of physically proximal sequences. We show that, unlike other targeted re-sequencing methods, TLA works without detailed prior locus information, as one or a few primer pairs are sufficient for sequencing tens to hundreds of kilobases of surrounding DNA.
View Article and Find Full Text PDFContext: Pheochromocytoma-paraganglioma syndrome is caused by mutations in SDHB, SDHC, and SDHD, encoding subunits of succinate dehydrogenase (SDH), and in SDHAF2, required for flavination of SDHA. A recent report described a patient with an abdominal paraganglioma, immunohistochemically negative for SDHA, and identified a causal germline mutation in SDHA.
Objective: In this study, we evaluated the significance of SDHA immunohistochemistry in the identification of new patients with SDHA mutations.
Purpose Of Review: Premature ovarian insufficiency (POI) is a common disorder affecting approximately 1% of women under the age of 40 years. Until now, research aiming to identify genetic causes of POI was mostly based on candidate gene approaches. Recently, several genes have been identified using this approach, and genome-wide searches were conducted.
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