Publications by authors named "Kristof van Schil"

Background: encodes an intracellular inhibitor of the bone morphogenetic protein (BMP) signalling pathway. Until now, rare heterozygous loss-of-function variants in were demonstrated to increase the risk of disparate clinical disorders including cardiovascular disease, craniosynostosis and radioulnar synostosis. Only two unrelated patients harbouring biallelic variants presenting a complex cardiovascular phenotype and facial dysmorphism have been described.

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The implementation of whole exome sequencing (WES) has had a major impact on the diagnostic yield of genetic testing in individuals with epilepsy. The identification of a genetic etiology paves the way to precision medicine: an individualized treatment approach, based on the disease pathophysiology. The aim of this retrospective cohort study was to: (1) determine the diagnostic yield of WES in a heterogeneous cohort of individuals with epilepsy referred for genetic testing in a real-world clinical setting, (2) investigate the influence of epilepsy characteristics on the diagnostic yield, (3) determine the theoretical yield of treatment changes based on genetic diagnosis and (4) explore the barriers to implementation of precision medicine.

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Recessive pathogenic variants in POPDC3 have recently been associated with the rare limb-girdle muscular dystrophy (LGMD) subtype LGMDR26. We studied three siblings and a distantly related individual with a skeletal muscle disorder, harboring the c.486-6T>A splice site variant in POPDC3 in homozygosity.

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Defects in primary or motile cilia result in a variety of human pathologies, and retinal degeneration is frequently associated with these so-called ciliopathies. We found that homozygosity for a truncating variant in CEP162, a centrosome and microtubule-associated protein required for transition zone assembly during ciliogenesis and neuronal differentiation in the retina, caused late-onset retinitis pigmentosa in 2 unrelated families. The mutant CEP162-E646R*5 protein was expressed and properly localized to the mitotic spindle, but it was missing from the basal body in primary and photoreceptor cilia.

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Objective: To investigate the diagnostic yield of targeted next-generation sequencing using hearing loss panels and to identify patient-related factors that are associated with a definite genetic cause.

Study Design: Retrospective chart review.

Setting: Tertiary referral center.

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Congenital hearing loss has an impact on almost every facet of life. In more than 50% of cases, a genetic cause can be identified. Currently, extensive genetic testing is available, although the etiology of some patients with obvious familial hearing loss remains unknown.

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Familial primary desminopathies are usually autosomal dominantly inherited and present at the age of 20 to 40 years with progressive muscle weakness and atrophy, cardiomyopathy, and cardiac arrhythmias. Cardiac features may precede the muscular weakness. Here, we report the rare case of two siblings presenting with a desminopathy at pediatric age, due to homozygous nonsense variations (c.

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Biallelic variants of the gene encoding for the zinc-finger protein 142 (ZNF142) have recently been associated with intellectual disability (ID), speech impairment, seizures, and movement disorders in nine individuals from five families. In this study, we obtained phenotype and genotype information of 26 further individuals from 16 families. Among the 27 different ZNF142 variants identified in the total of 35 individuals only four were missense.

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Mutations in HNRNPA1 encoding heterogeneous nuclear ribonucleoprotein (hnRNP) A1 are a rare cause of amyotrophic lateral sclerosis (ALS) and multisystem proteinopathy (MSP). hnRNPA1 is part of the group of RNA-binding proteins (RBPs) that assemble with RNA to form RNPs. hnRNPs are concentrated in the nucleus and function in pre-mRNA splicing, mRNA stability, and the regulation of transcription and translation.

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Congenital cone-rod synaptic disorder (CRSD), also known as incomplete congenital stationary night blindness (iCSNB), is a non-progressive inherited retinal disease (IRD) characterized by night blindness, photophobia, and nystagmus, and distinctive electroretinographic features. Here, we report bi-allelic RIMS2 variants in seven CRSD-affected individuals from four unrelated families. Apart from CRSD, neurodevelopmental disease was observed in all affected individuals, and abnormal glucose homeostasis was observed in the eldest affected individual.

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The original version of this Article contained an incorrect version of Fig. 3, which included two variants initially shown in black text in Fig. 3a that the authors removed from the final manuscript.

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Purpose: RAX2 encodes a homeobox-containing transcription factor, in which four monoallelic pathogenic variants have been described in autosomal dominant cone-dominated retinal disease.

Methods: Exome sequencing in a European cohort with inherited retinal disease (IRD) (n = 2086) was combined with protein structure modeling of RAX2 missense variants, bioinformatics analysis of deletion breakpoints, haplotyping of RAX2 variant c.335dup, and clinical assessment of biallelic RAX2-positive cases and carrier family members.

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The original version of this Article contained an error in the spelling of the author Anja K. Mayer, which was incorrectly given as Anja Kathrin Mayer. This has now been corrected in both the PDF and HTML versions of the Article.

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PurposePart of the hidden genetic variation in heterogeneous genetic conditions such as inherited retinal diseases (IRDs) can be explained by copy-number variations (CNVs). Here, we explored the genomic landscape of IRD genes listed in RetNet to identify and prioritize those genes susceptible to CNV formation.MethodsRetNet genes underwent an assessment of genomic features and of CNV occurrence in the Database of Genomic Variants and literature.

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Purpose: Our goal was to design a customized microarray, arrEYE, for high-resolution copy number variant (CNV) analysis of known and candidate genes for inherited retinal dystrophy (iRD) and retina-expressed noncoding RNAs (ncRNAs).

Methods: arrEYE contains probes for the full genomic region of 106 known iRD genes, including those implicated in retinitis pigmentosa (RP) (the most frequent iRD), cone-rod dystrophies, macular dystrophies, and an additional 60 candidate iRD genes and 196 ncRNAs. Eight CNVs in iRD genes identified by other techniques were used as positive controls.

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Article Synopsis
  • The study investigates the molecular causes of a specific retinitis pigmentosa (RP) phenotype in a Turkish family, identifying two potential candidate genes: SAMD7 and RHO.
  • A mutation in the RHO gene was found in affected siblings, while variants in the SAMD7 gene, particularly in regions that interact with the retinal transcription factor CRX, were also noted.
  • Functional assays indicated that these SAMD7 variants reduce the gene’s expression, suggesting they may play a role in the unique retinal phenotype observed in the family members.
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Purpose: To determine the disease course of retinal dystrophy caused by recessive variants in the DRAM2 (damage-regulated autophagy modulator 2) gene.

Methods: Sixteen individuals with DRAM2-retinopathy were examined (six families; age range, 19-56 years, includes one pre-symptomatic case). The change in visual acuity over time was studied, and electrophysiology (n = 6), retina-tracking perimetry (n = 1), fundus autofluorescence (FAF) imaging (n = 6), and optical coherence tomography (OCT; n = 12) were performed.

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Purpose: To identify mutations in FAM161A underlying autosomal recessive retinitis pigmentosa (arRP) in the Dutch and Belgian populations and to investigate whether common FAM161A-associated phenotypic features could be identified.

Methods: Homozygosity mapping, amplification-refractory mutation system (ARMS) analysis, and Sanger sequencing were performed to identify mutations in FAM161A. Microsatellite and SNP markers were genotyped for haplotype analysis.

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Retinal dystrophies are an overlapping group of genetically heterogeneous conditions resulting from mutations in more than 250 genes. Here we describe five families affected by an adult-onset retinal dystrophy with early macular involvement and associated central visual loss in the third or fourth decade of life. Affected individuals were found to harbor disease-causing variants in DRAM2 (DNA-damage regulated autophagy modulator protein 2).

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Purpose: The aim of this study was to identify the genetic cause of early-onset autosomal recessive cerebellar ataxia associated with retinal dystrophy in a consanguineous family.

Methods: An affected 6-month-old child underwent neurological and ophthalmological examinations. Genetic analyses included homozygosity mapping, copy number analysis, conventional polymerase chain reaction, Sanger sequencing, quantitative polymerase chain reaction, and whole-exome sequencing.

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Purpose: Autosomal recessive retinal dystrophies are clinically and genetically heterogeneous, which hampers molecular diagnosis. We evaluated identity-by-descent-guided Sanger sequencing or whole-exome sequencing in 26 families with nonsyndromic (19) or syndromic (7) autosomal recessive retinal dystrophies to identify disease-causing mutations.

Methods: Patients underwent genome-wide identity-by-descent mapping followed by Sanger sequencing (16) or whole-exome sequencing (10).

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