Publications by authors named "Femke C C Klouwer"

Background: Bile acid synthesis defects (BASDs) can be severely disabling involving the liver and nervous system, potentially due to elevated levels of toxic C-bile acid intermediates. Cholic acid (CA) supplementation is hypothesized to decrease bile acid production, stimulate bile secretion and -flow, and slowing down disease progression. This systematic review assesses the clinical and biochemical effectiveness, and safety of CA in BASDs patients.

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Article Synopsis
  • Alpha-methylacyl-CoA racemase (AMACR) deficiency is a rare genetic disorder that causes the buildup of toxic bile acids and has been minimally studied, with fewer than 20 documented cases.
  • A recent study involving 12 patients revealed that symptoms like retinitis pigmentosa and neurological issues typically develop in adults after a significant delay in diagnosis, with a median age of 56 years at the time of identification.
  • The condition presents primarily as a slowly progressive neurological disease, and MRI scans can help identify characteristic brain abnormalities, highlighting the need for better recognition and awareness of AMACR deficiency.
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Purpose: This cross-sectional study describes the ophthalmological and general phenotype of 10 patients from six different families with a comparatively mild form of Zellweger spectrum disorder (ZSD), a rare peroxisomal disorder.

Methods: Ophthalmological assessment included best-corrected visual acuity (BCVA), perimetry, microperimetry, ophthalmoscopy, fundus photography, spectral-domain optical coherence tomography (SD-OCT), and fundus autofluorescence (FAF) imaging. Medical records were reviewed for medical history and systemic manifestations of ZSD.

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  • * A study analyzed 29 confirmed ADA2 deficiency patients, discovering that 66% had neurological manifestations, primarily transient ischemic attacks (TIA) or ischemic strokes, with a notable decrease in recurrence after starting TNF-α inhibitor therapy.
  • * The findings highlight the importance of recognizing ADA2 deficiency as a treatable cause of strokes in young patients, emphasizing the need for awareness among neurologists and pediatricians to facilitate timely diagnosis and care.
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Deficiency of adenosine deaminase-2 (DADA2) is an autosomal recessive autoinflammatory disease with an extremely variable disease presentation. This paper provides a comprehensive overview of the Dutch DADA2 cohort. We performed a retrospective cohort study in 29 ADA2-deficient patients from 23 families with a median age at inclusion of 26 years.

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Article Synopsis
  • DADA2 is a recessive disease leading to issues like systemic vasculitis and early-onset stroke, affecting both kids and adults, with over 35,000 cases globally and no current management guidelines.
  • The DADA2 Consensus Committee, including patient representatives and experts from 18 countries, created 32 consensus statements to improve diagnostic testing, screening, and treatment based on patient symptoms.
  • Early diagnosis and treatment of DADA2 are crucial, and these consensus statements aim to provide a structured approach for doctors in evaluating and managing the disease.
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Inborn errors of metabolism are genetic disorders that need to be recognized as early as possible because treatment may be available. In late-onset forms, core symptoms are movement disorders, psychiatric symptoms, and cognitive impairment. Eye movement disorders are considered to be frequent too, although specific knowledge is lacking.

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Peroxisome biogenesis disorders within the Zellweger spectrum (PBD-ZSDs) are most frequently associated with the c.2528G>A (p.G843D) mutation in the gene (PEX1-G843D), which results in impaired import of peroxisomal matrix proteins and, consequently, defective peroxisomal functions.

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Patients with a Zellweger spectrum disorder (ZSD) have a defect in the assembly or maintenance of peroxisomes, leading to a multisystem disease with variable outcome. Liver disease is an important feature in patients with severe and milder phenotypes and a frequent cause of death. However, the course and histology of liver disease in ZSD patients are ill-defined.

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Introduction: Currently, no therapies are available for Zellweger spectrum disorders (ZSDs), a group of genetic metabolic disorders characterised by a deficiency of functional peroxisomes. In a previous study, we showed that oral cholic acid (CA) treatment can suppress bile acid synthesis in ZSD patients and, thereby, decrease plasma levels of toxic C -bile acid intermediates, one of the biochemical abnormalities in these patients. However, no effect on clinically relevant outcome measures could be observed after 9 months of CA treatment.

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Zellweger spectrum disorders (ZSDs) are autosomal-recessive disorders that are caused by defects in peroxisome biogenesis due to bi-allelic mutations in any of 13 different PEX genes. Here, we identified seven unrelated individuals affected with an apparent dominant ZSD in whom a heterozygous mutant PEX6 allele (c.2578C>T [p.

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Introduction: Zellweger spectrum disorders (ZSDs) are caused by an impairment of peroxisome biogenesis, resulting in multiple metabolic abnormalities. This leads to a range of symptoms, including hepatic dysfunction and coagulopathy. This study evaluated the incidence and severity of coagulopathy and the effect of vitamin K supplementation orally and IV in ZSD.

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X-linked adrenoleukodystrophy (ALD) is the most common leukodystrophy with a birth incidence of 1:14,700 live births. The disease is caused by mutations in ABCD1 and characterized by very long-chain fatty acids (VLCFA) accumulation. In childhood, male patients are at high-risk to develop adrenal insufficiency and/or cerebral demyelination.

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Introduction: Zellweger spectrum disorders (ZSD) are a group of genetic metabolic disorders caused by a defect in peroxisome biogenesis. This results in multiple metabolic abnormalities, including elevated very long-chain fatty acid (VLCFA) levels. Elevated levels of C26:0-lysophosphatidylcholine (C26:0-lysoPC) have been shown in dried blood spots (DBS) from ZSD patients.

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The peroxisomal disorders (PDs) are a heterogeneous group of genetic diseases in man caused by an impairment in peroxisome biogenesis or one of the metabolic functions of peroxisomes. Thanks to the revolutionary technical developments in gene sequencing methods and their increased use in patient diagnosis, the field of genetic diseases in general and peroxisomal disorders in particular has dramatically changed in the last few years. Indeed, several novel peroxisomal disorders have been identified recently and in addition it has been realized that the phenotypic spectrum of patients affected by a PD keeps widening, which makes clinical recognition of peroxisomal patients increasingly difficult.

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Objective: The hypothalamus-pituitary-thyroid (HPT) axis set point develops during the fetal period and first two years of life. We hypothesized that thyroxine treatment during these first two years, in the context of a randomized controlled trial (RCT) in children with Down syndrome, may have influenced the HPT axis set point and may also have influenced the development of Down syndrome-associated autoimmune thyroiditis.

Methods: We included 123 children with Down syndrome 8.

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The immortalized human hepatocyte (IHH) cell line is increasingly used for studies related to liver metabolism, including hepatic glucose, lipid, lipoprotein and triglyceride metabolism, and the effect of therapeutic interventions. To determine whether the IHH cell line is a good model to investigate hepatic peroxisomal metabolism, we measured several peroxisomal parameters in IHH cells and, for comparison, HepG2 cells and primary skin fibroblasts. This revealed a marked plasmalogen deficiency and a deficient fatty acid α-oxidation in the IHH cells, due to a defect of PEX7, a cytosolic receptor protein required for peroxisomal import of a subset of peroxisomal proteins.

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Introduction: Zellweger spectrum disorders (ZSDs) are characterized by a failure in peroxisome formation, caused by autosomal recessive mutations in different PEX genes. At least some of the progressive and irreversible clinical abnormalities in patients with a ZSD, particularly liver dysfunction, are likely caused by the accumulation of toxic bile acid intermediates. We investigated whether cholic acid supplementation can suppress bile acid synthesis, reduce accumulation of toxic bile acid intermediates and improve liver function in these patients.

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Peroxisomal disorders are a heterogeneous group of genetic metabolic disorders, caused by a defect in peroxisome biogenesis or a deficiency of a single peroxisomal enzyme. The peroxisomal disorders include the Zellweger spectrum disorders, the rhizomelic chondrodysplasia punctata spectrum disorders, X-linked adrenoleukodystrophy, and multiple single enzyme deficiencies. There are several core phenotypes caused by peroxisomal dysfunction that clinicians can recognize.

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Zellweger spectrum disorders (ZSDs) represent the major subgroup within the peroxisomal biogenesis disorders caused by defects in PEX genes. The Zellweger spectrum is a clinical and biochemical continuum which can roughly be divided into three clinical phenotypes. Patients can present in the neonatal period with severe symptoms or later in life during adolescence or adulthood with only minor features.

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Leukoencephalopathy with thalamus and brainstem involvement and high lactate (LTBL) is caused by autosomal recessive EARS2 mutations. Onset is most often in infancy, but in severe cases in the neonatal period. Patients typically have magnetic resonance imaging (MRI) signal abnormalities involving the thalamus, brainstem, and deep cerebral white matter.

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Context: In 2-year-old children with Down's syndrome (DS), early T4 treatment was found to result in slightly better motor development and growth.

Objectives: This study sought to determine long-term effects of early T4 treatment on development and growth in children with DS with either an elevated or normal neonatal TSH concentration.

Design: Patients received a single follow-up visit 8.

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