Publications by authors named "Levinus A Bok"

Background And Objectives: Pyridoxine-dependent epilepsy (PDE-ALDH7A1) is a developmental epileptic encephalopathy characterized by seizure improvement after pyridoxine supplementation. Adjunct lysine reduction therapies (LRTs) reduce the accumulation of putative neurotoxic metabolites with the goal to improve developmental outcomes. Our objective was to examine the association between treatment with LRTs and cognitive outcomes.

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Background: Transitioning from paediatric medical care to adult care is a challenging process for children, parents and healthcare professionals. The aim of this study was to explore the experiences, concerns and needs of parents of children with Down syndrome and of professionals regarding this transition.

Method: A qualitative study was performed using semi-structured interviews with 20 parents of children with Down syndrome and six healthcare professionals.

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Background: Seventy-five percent of patients with pyridoxine-dependent epilepsy due to α-aminoadipic semialdehyde dehydrogenase deficiency (PDE-ALDH7A1) suffer intellectual developmental disability despite pyridoxine treatment. Adjunct lysine reduction therapies (LRT), aimed at lowering putative neurotoxic metabolites, are associated with improved cognitive outcomes. However, possibly due to timing of treatment, not all patients have normal intellectual function.

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Nucleotide metabolism is a complex pathway regulating crucial cellular processes such as nucleic acid synthesis, DNA repair and proliferation. This study shows that impairment of the biosynthesis of one of the building blocks of DNA, dTTP, causes a severe, early-onset neurodegenerative disease. Here, we describe two unrelated children with bi-allelic variants in DTYMK, encoding dTMPK, which catalyzes the penultimate step in dTTP biosynthesis.

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Purpose: The aim of this study was to retrospectively analyze the effect of the Sharrard procedure on hip instability in children with Down syndrome (DS), as measured by the migration index.

Methods: In total, 17 children (21 hips) were included from six hospitals in the Netherlands between 2003 and 2019. The primary outcome, hip instability, was assessed with the Reimers' migration index on preoperative and postoperative plain anteroposterior pelvic radiographs.

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BackgroundPyridoxine-dependent epilepsy (PDE-ALDH7A1) is an inborn error of lysine catabolism that presents with refractory epilepsy in newborns. Biallelic ALDH7A1 variants lead to deficiency of α-aminoadipic semialdehyde dehydrogenase/antiquitin, resulting in accumulation of piperideine-6-carboxylate (P6C), and secondary deficiency of the important cofactor pyridoxal-5'-phosphate (PLP, active vitamin B6) through its complexation with P6C. Vitamin B6 supplementation resolves epilepsy in patients, but intellectual disability may still develop.

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Pyridoxine-dependent epilepsy (PDE-ALDH7A1) is an autosomal recessive condition due to a deficiency of α-aminoadipic semialdehyde dehydrogenase, which is a key enzyme in lysine oxidation. PDE-ALDH7A1 is a developmental and epileptic encephalopathy that was historically and empirically treated with pharmacologic doses of pyridoxine. Despite adequate seizure control, most patients with PDE-ALDH7A1 were reported to have developmental delay and intellectual disability.

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Background: People with chronic conditions have complex healthcare needs that lead to challenges for adequate healthcare provision. Current healthcare services do not always respond adequately to their needs. A modular perspective, in particular providing visualization of the modular service architecture, is promising for improving the responsiveness of healthcare services to the complex healthcare needs of people with chronic conditions.

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Objective: De novo missense mutations in the gene have been described as causative for developmental and epileptic encephalopathy.

Methods: The clinical phenotype of this disorder includes early-onset epilepsy, severe intellectual disability, postnatal microcephaly, and movement disorder. Three patients have been described with acute encephalopathy and febrile epileptic status.

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Guidelines for children with Down syndrome (DS) suggest to perform an annual hip screening to enable early detection of developmental dysplasia of the hip (DDH). How to perform this screening is not described. Delayed detection can result in disabling osteoarthritis of the hip.

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Article Synopsis
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Purpose: Pathogenic variants in ARID1B are one of the most frequent causes of intellectual disability (ID) as determined by large-scale exome sequencing studies. Most studies published thus far describe clinically diagnosed Coffin-Siris patients (ARID1B-CSS) and it is unclear whether these data are representative for patients identified through sequencing of unbiased ID cohorts (ARID1B-ID). We therefore sought to determine genotypic and phenotypic differences between ARID1B-ID and ARID1B-CSS.

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Objective: To evaluate the features and maturational changes in overall callosal shape in patients with pyridoxine-dependent epilepsy (PDE).

Methods: Measurements were conducted through landmark-based geometric morphometrics applied on cerebral MRIs of patients with PDE and age-matched control subjects. The outline of the corpus callosum was manually traced in the midsagittal plane.

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Although the role of typical Rho GTPases and other Rho-linked proteins in synaptic plasticity and cognitive function and dysfunction is widely acknowledged, the role of atypical Rho GTPases (such as RHOBTB2) in neurodevelopment has barely been characterized. We have now identified de novo missense variants clustering in the BTB-domain-encoding region of RHOBTB2 in ten individuals with a similar phenotype, including early-onset epilepsy, severe intellectual disability, postnatal microcephaly, and movement disorders. Three of the variants were recurrent.

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Background: De novo mutations in have recently been described to cause PURA syndrome, a neurodevelopmental disorder characterised by severe intellectual disability (ID), epilepsy, feeding difficulties and neonatal hypotonia.

Objectives: To delineate the clinical spectrum of PURA syndrome and study genotype-phenotype correlations.

Methods: Diagnostic or research-based exome or Sanger sequencing was performed in individuals with ID.

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Kleefstra syndrome, caused by haploinsufficiency of euchromatin histone methyltransferase 1 (EHMT1), is characterized by intellectual disability (ID), autism spectrum disorder (ASD), characteristic facial dysmorphisms, and other variable clinical features. In addition to EHMT1 mutations, de novo variants were reported in four additional genes (MBD5, SMARCB1, NR1I3, and KMT2C), in single individuals with clinical characteristics overlapping Kleefstra syndrome. Here, we present a novel cohort of five patients with de novo loss of function mutations affecting the histone methyltransferase KMT2C.

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Sequencing studies have implicated haploinsufficiency of , a SWI/SNF chromatin-remodeling subunit, in short stature (Yu et al., 2015), autism spectrum disorder (O'Roak et al., 2012), intellectual disability (Deciphering Developmental Disorders Study, 2015), and corpus callosum agenesis (Halgren et al.

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A giant intracranial aneurysm was diagnosed in a 10-year-old girl when she developed a right abducens nerve palsy. The aneurysm was treated successfully. Six years later, however, she presented with a progressive deformity, leading to the diagnosis Parry Romberg Syndrome (PRS), a rare diagnosis characterized by hemifacial atrophy of skin, subcutaneous tissue, skeletal muscle and bones and often associated with various non-specific intracerebral abnormalities.

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Background: We aimed for a comprehensive delineation of genetic, functional and phenotypic aspects of encephalopathy and explored potential prospects of personalised medicine.

Methods: Data of 48 individuals with de novo variants were collected from several diagnostic and research cohorts, as well as from 43 patients from the literature. Functional consequences and response to memantine treatment were investigated in vitro and eventually translated into patient care.

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Background: Recent decades have unravelled the molecular background of a number of inborn errors of metabolism (IEM) causing vitamin B6-dependent epilepsy. As these defects interfere with vitamin B6 metabolism by different mechanisms, the plasma vitamin B6 profile can give important clues for further molecular work-up. This has so far been investigated in only a small number of patients.

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Purpose: Truncating mutations in the maternally imprinted, paternally expressed gene MAGEL2, which is located in the Prader-Willi critical region 15q11-13, have recently been reported to cause Schaaf-Yang syndrome, a Prader-Willi-like disease that manifests as developmental delay/intellectual disability, hypotonia, feeding difficulties, and autism spectrum disorder. The causality of the reported variants in the context of the patients' phenotypes was questioned, as MAGEL2 whole-gene deletions seem to cause little or no clinical phenotype.

Methods: Here we report a total of 18 newly identified individuals with Schaaf-Yang syndrome from 14 families, including 1 family with 3 individuals found to be affected with a truncating variant of MAGEL2, 11 individuals who are clinically affected but were not tested molecularly, and a presymptomatic fetal sibling carrying the pathogenic MAGEL2 variant.

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Background: Chest compressions (CC) during cardiopulmonary resuscitation (CPR) are the cornerstone of adult CPR protocols and are meant to restore circulation and improve outcome. Although adverse effects such as air-embolisms have been reported, these are rare and considered to be outweighed by beneficial effect. In newborns, however, the lung tissue is more fragile.

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