0000000000620394

AUTHOR

Robert M.w. Hofstra

Biallelic variants in LARS2 and KARS cause deafness and (ovario)leukodystrophy

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No major role for periconceptional folic acid use and its interaction with theMTHFR C677Tpolymorphism in the etiology of congenital anorectal malformations

Background: Both genetic and nongenetic factors are suggested to be involved in the etiology of congenital anorectal malformations (ARM). Maternal periconceptional use of folic acid supplements were inconsistently suggested to play a role in the prevention of ARM. Therefore, we investigated independent associations and interactions of maternal periconceptional folic acid supplement use and the infant and maternal MTHFR (methylenetetrahydrofolate reductase) C677T polymorphisms with the risk of ARM and subgroups of ARM. Methods: A case-control study was conducted among 371 nonsyndromic ARM cases and 714 population-based controls born between 1990 and 2012 using maternal questionnaires and DNA…

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Analysis of the RET, GDNF, EDN3, and EDNRB genes in patients with intestinal neuronal dysplasia and Hirschsprung disease

BACKGROUNDHirschsprung disease (HSCR) is a frequent congenital disorder with an incidence of 1 in 5000 live births, characterised by the absence of parasympathetic intramural ganglion cells in the hindgut resulting in intestinal obstruction in neonates and severe constipation in infants and adults. Intestinal neuronal dysplasia (IND) shares clinical features with HSCR but the submucosal parasympathetic plexus is affected. IND has been proposed as one of the most frequent causes of chronic constipation and is often associated with HSCR.METHODSWe examined 29 patients diagnosed with sporadic HSCR, 20 patients with IND, and 12 patients with mixed HSCR/IND for mutations in the coding regions of …

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L1 syndrome diagnosis complemented with functional analysis of L1CAM variants located to the two N-terminal Ig-like domains

L1CAM gene mutations cause neurodevelopmental disorders collectively termed L1 syndrome. Insufficient information about L1CAM variants complicates clinical prognosis, genetic diagnosis and genetic counseling. We combined clinical data, in silico effect predictions and functional analysis of four L1CAM variants, p.I37N, p.T38M, p.M172I and p.D202Y, located to the two N-terminal Ig-like domains present in five families with symptoms of L1 syndrome. Software tools predicted destabilizing effects of p.I37N and p.D202Y but results for p.T38M and p.M172I were inconsistent. Cell surface expression of mutant proteins L1-T38M, L1-M172I and L1-D202Y was normal. Conversely, L1-I37N accumulated in the …

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Exome chip association study excluded the involvement of rare coding variants with large effect sizes in the etiology of anorectal malformations

IntroductionAnorectal malformations (ARM) are rare congenital malformations, resulting from disturbed hindgut development. A genetic etiology has been suggested, but evidence for the involvement of specific genes is scarce. We evaluated the contribution of rare and low-frequency coding variants in ARM etiology, assuming a multifactorial model.MethodsWe analyzed 568 Caucasian ARM patients and 1,860 population-based controls using the Illumina Human Exome Beadchip array, which contains >240,000 rare and low-frequency coding variants. GenomeStudio clustering and calling was followed by re-calling of 'no-calls' using zCall for patients and controls simultaneously. Single variant and gene-bas…

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