Ben J. H. M. Poorthuis

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OBJECTIVE Mucopolysaccharidosis (MPS) IIIA (Sanfilippo syndrome type A) is a lysosomal storage disorder caused by deficiency of the enzyme sulfamidase. Information on the natural course of MPS IIIA is scarce, but is much needed in view of emerging therapies. METHODS Clinical history and molecular defects of all 110 MPS IIIA patients identified by(More)
The twitcher mouse is an animal model of galactosylceramidase deficiency, comparable to Krabbe's disease, a lysosomal storage disease in humans. As in most lysosomal storage diseases, neurological deterioration is a prominent feature of the disease in these mice. Transplantation of enzymatically normal congenic bone marrow was earlier found to result in(More)
Mucopolysaccharidosis type IIIB (MPS IIIB, Sanfilippo syndrome type B) is a lysosomal storage disorder caused by deficiency of the enzyme N-acetyl-α-D-glucosaminidase (NAGLU). Information on the natural course of MPS IIIB is scarce but much needed in view of emerging therapies. To improve knowledge on the natural course, data on all 52 MPS IIIB patients(More)
Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) is caused by mutations in the gene encoding thymidine phosphorylase (TP). All MNGIE patients have had severe loss of TP function and prominent plasma accumulations of the TP substrates thymidine (dThd) and deoxyuridine (dUrd). Here, we report for the first time to our knowledge three MNGIE(More)
The peripheral nerve of the homozygous twitcher mouse (twi/twi), a murine model of globoid cell leukodystrophy (GLD), was examined following bone marrow transplantation (BMT). The light and electron microscopic studies revealed markedly increased numbers of remyelinated fibers and almost complete disappearance of the typical inclusion-laden macrophages in(More)
A biomarker is an analyte indicating the presence of a biological process linked to the clinical manifestations and outcome of a particular disease. In the case of lysosomal storage disorders (LSDs), primary and secondary accumulating metabolites or proteins specifically secreted by storage cells are good candidates for biomarkers. Clinical applications of(More)
Very long chain acyl-coenzyme A (acyl-CoA) dehydrogenase (VLCAD) deficiency is a severe disorder of mitochondrial beta-oxidation in infants. We report adult onset of attacks of painful rhabdomyolysis. Gas chromatography identified strongly elevated levels of tetradecenoic acid, 14:1(n-9), tetradecadienoic acid, 14:2(n-6), and hexadecadienoic acid,(More)
INTRODUCTION Enzyme replacement therapy (ERT) with alpha-Galactosidase A (aGal A) may cause antibody (AB) formation against aGal A in males with Fabry disease (FD). Anti agalsidase ABs negatively influence globotriaosylceramide (Gb3) reduction. We investigated the impact of agalsidase AB on Gb3 and lysoGb3 and clinical outcome in Fabry patients on ERT. (More)
BACKGROUND Simple, reproducible assays are needed for the quantification of sphingolipids, ceramide (Cer), and sphingoid bases. We developed an HPLC method for simultaneous quantification of total plasma concentrations of Cer, glucosylceramide (GlcCer), and ceramide trihexoside (CTH). METHODS After addition of sphinganine as internal calibrator, we(More)
BACKGROUND Enzyme replacement therapy is currently the only approved therapy for Fabry disease. From June 2009 on, viral contamination of Genzyme's production facility resulted in a worldwide shortage of agalsidase beta leading to involuntary dose reductions (approved dose 1 mg/kg/eow, reduced dose 0.5 mg/kg/m), or switch to agalsidase alpha (administered(More)