The birth prevalence of lysosomal storage disorders in the Czech Republic: comparison with data in different populations

The aim of this retrospective study was to determine the prevalence of lysosomal storage disorders (LSDs) in the Czech Republic. The data on cases diagnosed between 1975 and 2008 were collected and analyzed. The overall prevalence of LSDs in the Czech population (12.25 per 100,000) is comparable to that reported for the countries with well-established and advanced diagnostics of LSDs such as the Netherlands (14 per 100,000), Australia (12.9 per 100,000) and Italy (12.1 per 100,000). Relatively higher prevalence of LSDs was reported in the north of Portugal (25 per 100,000). Thirty-four different LSDs were diagnosed in a total of 478 individuals. Gaucher disease was the most frequent LSD with a birth prevalence of 1.13 per 100,000 births. The most frequent LSD groups were lipidoses, mucopolysaccharidoses, and neuronal ceroid lipofuscinoses, with combined prevalences of 5.0, 3.72, and 2.29 per 100,000 live births, respectively. Glycoproteinoses (0.57 per 100,000 live births), glycogenosis type II (0.37), and mucolipidoses (0.31) rarely occur in the Czech population, and a range of other LSDs have not been detected at all over the past three decades. Knowledge of the birth prevalence and carrier frequency of particular disorders is important in genetic counselling for calculation of the risk for the disorder in the other members of affected families. Earlier diagnosis of these disorders will permit timely intervention and may also result in lowering of the number of newborns with LSDs

Abnormal nonstoring capillary endothelium: a novel feature of Gaucher disease. Ultrastructural study of dermal capillaries

Ultrastructural study of skin biopsies in two cases of Gaucher disease (GD) patients (types II and III) revealed hitherto unknown alteration of the blood capillary endothelial cells (ECs) featured by hypertrophy and numerous subplasmalemmal microvesicles underneath both the apical and basal membranes. There was also prominent apical membrane folding with formation of filiform and large cytoplasmic projections, with occasional transcapillary cytoplasmic bridges. Similar, though less frequently expressed, changes were manifested at the basal membrane by numerous cytoplasmic projections into the subendothelial space. Regressive changes with EC breakdown were rare. Lysosomal storage was always absent. Besides EC hypertrophy, there was also increased EC density in the capillary lumen, leading to pronounced changes in capillary architecture with loose or incomplete EC anchoring. There were also signs of EC sprouting. Some pericytes displayed an increase in size and number of cytoplasmic processes, which often extended into distant pericapillary regions. The spectrum of changes suggests that a significant positive growth effect on EC occurs in GD. The putative mechanisms triggered by GBA1 deficiency leading to EC involvement are discussed. The authors are well aware of the fact the results, based on a nontraditional type of bioptic samples, are preliminary, but they are worth following, as further ultrastructural and functional studies of blood endothelium in GD may open a novel field in molecular cell pathophysiology of the disorder: endothelial dysfunction

Characterization of gana-1, a Caenorhabditis elegans gene encoding a single ortholog of vertebrate α-galactosidase and α-N-acetylgalactosaminidase

BACKGROUND: Human α-galactosidase A (α-GAL) and α-N-acetylgalactosaminidase (α-NAGA) are presumed to share a common ancestor. Deficiencies of these enzymes cause two well-characterized human lysosomal storage disorders (LSD) – Fabry (α-GAL deficiency) and Schindler (α-NAGA deficiency) diseases. Caenorhabditis elegans was previously shown to be a relevant model organism for several late endosomal/lysosomal membrane proteins associated with LSDs. The aim of this study was to identify and characterize C. elegans orthologs to both human lysosomal luminal proteins α-GAL and α-NAGA. RESULTS: BlastP searches for orthologs of human α-GAL and α-NAGA revealed a single C. elegans gene (R07B7.11) with homology to both human genes (α-galactosidase and α-N-acetylgalactosaminidase) – gana-1. We cloned and sequenced the complete gana-1 cDNA and elucidated the gene organization. Phylogenetic analyses and homology modeling of GANA-1 based on the 3D structure of chicken α-NAGA, rice α-GAL and human α-GAL suggest a close evolutionary relationship of GANA-1 to both human α-GAL and α-NAGA. Both α-GAL and α-NAGA enzymatic activities were detected in C. elegans mixed culture homogenates. However, α-GAL activity on an artificial substrate was completely inhibited by the α-NAGA inhibitor, N-acetyl-D-galactosamine. A GANA-1::GFP fusion protein expressed from a transgene, containing the complete gana-1 coding region and 3 kb of its hypothetical promoter, was not detectable under the standard laboratory conditions. The GFP signal was observed solely in a vesicular compartment of coelomocytes of the animals treated with Concanamycin A (CON A) or NH(4)Cl, agents that increase the pH of the cellular acidic compartment. Immunofluorescence detection of the fusion protein using polyclonal anti-GFP antibody showed a broader and coarsely granular cytoplasmic expression pattern in body wall muscle cells, intestinal cells, and a vesicular compartment of coelomocytes. Inhibition of gana-1 by RNA interference resulted in a decrease of both α-GAL and α-NAGA activities measured in mixed stage culture homogenates but did not cause any obvious phenotype. CONCLUSIONS: GANA-1 is a single C. elegans ortholog of both human α-GAL and α-NAGA proteins. Phylogenetic, homology modeling, biochemical and GFP expression analyses support the hypothesis that GANA-1 has dual enzymatic activity and is localized in an acidic cellular compartment

Atypical CLN2 with later onset and prolonged course: a neuropathologic study showing different sensitivity of neuronal subpopulations to TPP1 deficiency

This is the first neuropathology report of a male patient (born 1960–died 1975) with an extremely rare, atypical variant of CLN2 that has been diagnosed only in five families so far. The clinical history started during his preschool years with relatively mild motor and psychological difficulties, but with normal intellect and vision. Since age six there were progressive cerebellar and extrapyramidal symptomatology, amaurosis, and mental deterioration. Epileptic seizures were absent. The child died aged 15 years in extreme cachexy. Neuropathology revealed neurolysosomal storage of autofluorescent, curvilinear and subunit c of mitochondrial ATP synthase (SCMAS) rich material. The neuronal storage led to laminar neuronal depopulation in the cerebral cortex and to a practically total eradication of the cerebellar cortical neurons. The other areas of the central nervous system including hippocampus, which are usually heavily affected in classical forms of CLN2, displayed either a lesser degree or absence of neuronal storage, or storage without significant neuronal loss. Transformation of the stored material to the spheroid like perikaryal inclusions was rudimentary. The follow-up, after 30 years, showed heterozygous values of TPP1 (tripeptidylpeptidase 1) activity in the white blood cells of both parents and the sister. DNA analysis of CLN2 gene identified a paternal frequent null mutation c.622C > T (p.Arg208 X) in the 6th exon and a maternal novel mutation c.1439 T > G in exon 12 (p.Val480Gly). TPP1 immunohistochemistry using a specific antibody gave negative results in the brain and other organs. Our report supports the notion that the spectrum of CLN2 phenotypes may be surprisingly broad. The study revealed variable sensitivities in neuronal subpopulations to the metabolic defect which may be responsible for the variant’s serious course

Replacement of α-galactosidase A in Fabry disease: effect on fibroblast cultures compared with biopsied tissues of treated patients

The function and intracellular delivery of enzyme therapeutics for Fabry disease were studied in cultured fibroblasts and in the biopsied tissues of two male patients to show diversity of affected cells in response to treatment. In the mutant fibroblasts cultures, the final cellular level of endocytosed recombinant α-galactosidases A (agalsidases, FabrazymeTM, and ReplagalTM) exceeded, by several fold, the amount in control fibroblasts and led to efficient direct intra-lysosomal hydrolysis of (3H)Gb3Cer. In contrast, in the samples from the heart and some other tissues biopsied after several months of enzyme replacement therapy (ERT) with FabrazymeTM, only the endothelial cells were free of storage. Persistent Gb3Cer storage was found in cardiocytes (accompanied by increase of lipopigment), smooth muscle cells, fibroblasts, sweat glands, and skeletal muscle. Immunohistochemistry of cardiocytes demonstrated, for the first time, the presence of a considerable amount of the active enzyme in intimate contact with the storage compartment. Factors responsible for the limited ERT effectiveness are discussed, namely post-mitotic status of storage cells preventing their replacement by enzyme supplied precursors, modification of the lysosomal system by longstanding storage, and possible relative lack of Sap B. These observations support the strategy of early treatment for prevention of lysosomal storage

The coincidence of IgA nephropathy and Fabry disease

<p>Abstract</p> <p>Background</p> <p>IgA nephropathy (IgAN) is the most common glomerulonephritis, which may also coexist with other diseases. We present two patients with an unusual coincidence of IgAN and Fabry disease (FD).</p> <p>Case presentation</p> <p>A 26 year-old man underwent a renal biopsy in February 2001. Histopathology showed very advanced IgAN and vascular changes as a result of hypertension. Because of his progressive renal insufficiency the patient began hemodialysis in August 2001. By means of the blood spot test screening method the diagnosis of FD was suspected. Low activity of alpha-galactosidase A in the patient’s plasma and leukocytes and DNA analysis confirmed the diagnosis of FD. Enzyme replacement therapy started in July 2004. Then the patient underwent kidney transplantation in November 2005. Currently, his actual serum creatinine level is 250 μmol/l. Other organ damages included hypertrophic cardiomyopathy, neuropathic pain and febrile crisis. After enzyme replacement therapy, myocardial hypertrophy has stabilized and other symptoms have disappeared. No further progression of the disease has been noted.</p> <p>The other patient, a 30 year-old woman, suffered from long-term hematuria with a good renal function. Recently, proteinuria (2.6 g/day) appeared and a renal biopsy was performed. Histopathology showed IgAN with remarkably enlarged podocytes. A combination of IgAN and a high suspicion of FD was diagnosed. Electron microscopy revealed dense deposits in paramesangial areas typical for IgAN and podocytes with inclusive zebra bodies and myelin figures characteristic of FD. FD was confirmed by the decreased alpha-galactosidase A activity in plasma and leukocytes and by DNA and RNA analysis. Enzyme replacement therapy and family screening were initiated.</p> <p>Conclusions</p> <p>Our results emphasize the role of complexity in the process of diagnostic evaluation of kidney biopsy samples. Electron microscopy represents an integral part of histopathology, and genetic analysis plays a more and more important role in the final diagnosis, which is followed by causal treatment.</p