1/26. Two novel mutations of the arylsulfatase B gene in two Italian patients with severe form of mucopolysaccharidosis. Mutations in brief no. 127. Online.Mucopolysaccharidosis type VI (MPS VI) or Maroteaux-Lamy syndrome, is a autosomal recessive disorder, due to the deficiency of the lysosomal enzyme n-acetylgalactosamine-4-sulfatase (arylsufatase B, ASB: EC 3.1.6.12). Three classical forms of the disease have been differentiated: severe, intermediate, mild. Mutational analysis of the ASB gene resulted in the identification of 30 ASB mutant alleles, each of which was found to be unique among unrelated patients, demonstrating a broad molecular heterogeneity of the disease. In this communication we present two novel mutant alleles in two severely affected subjects. Both alterations, the missense mutation G302R and the nonsense Q456X, were found in homozygosity and were confirmed by amplification refractory mutation system (ARMS) or restriction analysis. The missense G302R mutation concerns an amino acid which may be of special importance to the polypeptide, since 302 position is completely conserved in all the eukaryotic sulfatases aligned so far; the nonsense mutation Q456X leads to the translation of a putative mutant ASB protein lacking the last 78 amino acids with a loss of the 8 kD mature polypeptide, one of the two peptides generated by intralysosomal proteolytic processing of the 64kD precursor.- - - - - - - - - - ranking = 1keywords = lysosomal enzyme, enzyme (Clic here for more details about this article) |
2/26. umbilical cord blood transplantation for Maroteaux-Lamy syndrome (mucopolysaccharidosis type VI).Severe Maroteaux-Lamy syndrome (mucopolysaccharidosis type VI) is usually fatal by early adulthood. bone marrow transplantation is the only form of definitive enzyme replacement therapy available. A 5-year-old boy with Maroteaux-Lamy syndrome has successful recovery of bone marrow and enzymatic functions after umbilical cord blood transplant from his unaffected HLA-identical brother. Busulphan (16 mg/kg) and cyclophosphamide (200 mg/kg) were used as preparative chemotherapy with short methotrexate and long cyclosporin as prophylaxis against graft-versus-host disease (GVHD). A total of 6.08 x 10(7)/kg nucleated cells and 2.92 x 10(5)/kg CD34 cells were transplanted with neutrophil engraftment achieved on day 26. There was no evidence of acute and chronic GVHD. Fifteen months after transplant, a normal level of N-acetylgalactosamine-4-sulphatase activity was achieved despite mixed chimerism. There was clinical improvement of hepatosplenomegaly, facial and skin features, joint mobility and resolution of suppurative middle ear effusion. He returned to school and continued to perform well in academic studies. We report here the first successful umbilical cord blood transplant as treatment of Maroteaux-Lamy syndrome.- - - - - - - - - - ranking = 0.0025725982417464keywords = enzyme (Clic here for more details about this article) |
3/26. Findings in the anterior segment on ultrasound biomicroscopy in Maroteaux-Lamy syndrome.PURPOSE: Maroteaux-Lamy syndrome is one of the mucopolysaccharidoses caused by enzyme deficiency (arylsulfatase B) that leads to incomplete degradation and storage of dermatan sulfate. We report a case of mucopolysaccharidosis type VI (MPS VI; Maroteaux-Lamy syndrome) with corneal involvement and introduce ultrasound biomicroscopy (UBM) as an examination with which to follow disease progression in relation to deposition in cornea, angle, and iris. methods: We describe a 11-year-old boy with a clinical and laboratorial diagnosis of MPS VI who developed increasing bilateral corneal opacification and decreased visual acuity. He underwent two seriate UBM (50-MHz transducer) evaluations. RESULTS: UBM examination showed diffuse and homogeneous stromal hyper-reflective deposit in both eyes and an increase in peripheral corneal thickness throughout time. CONCLUSION: High-frequency ultrasound documentation of corneal deposit and anterior segment involvement in a patient with Maroteaux-Lamy syndrome is unique, and follow-up revealed thickening of the corneal periphery, which may be related to the progression of the disease (continuous mucopolysaccharide deposits in corneal stroma). UBM was used to locate and document the deposit, as well as to accompany the deposit's evolution, characterizing corneal changes and angle structure involvement.- - - - - - - - - - ranking = 0.021639659044986keywords = storage, enzyme (Clic here for more details about this article) |
4/26. Mucopolysaccharidosis type VI: Report of two Taiwanese patients and identification of one novel mutation.Mucopolysaccharidosis type VI (MPS VI) is an autosomal recessive lysosomal storage disease caused by a deficiency of N-acetylgalactosamine-4-sulphatase (arylsulfatase B, ASB). We report the clinical investigation and mutation analysis of two Taiwanese patients with severe (Case 1) and intermediate (Case 2) phenotypes of MPS VI. Three missense mutations and one polymorphism were identified. Case 1 was found to have a novel heteroallelic C-to-G transversion at nucleotide 1197 causing a phenylalanine to leucine substitution at residue 399 (Phe399Leu), and a heteroallelic Gln239Arg mutation. In Case 2, a heterozygous Cys192Arg mutation and a Val358Met polymorphism were identified. Among these three mutations, the Gln239Arg and Phe399Leu substitutions have so far been observed only in the Taiwanese population. The correlation between genotype and phenotype contributes to molecular pre- and post-natal diagnosis for MPS VI patients.- - - - - - - - - - ranking = 3.1027484055088keywords = lysosomal storage, lysosomal storage disease, storage, storage disease (Clic here for more details about this article) |
5/26. Histological and ultrastructural studies of the cornea in Maroteaux-Lamy syndrome.The author presents the histologic and electron-microscopic examination of the cornea of a patient with Maroteaux-Lamy syndrome. Histochemic examinations established the absence of keratin sulfate and heparin sulfate in the accumulated material. By means of electron microscopy three cell types have been found in the stroma which may show, besides the storage of the accumulated glycosaminoglycans, the morphologic signs of the pathologic enzyme-substrate connection. Considering the presence of the lipidlike material, the question arises whether the Maroteaux-Lamy syndrome belongs to mucolipidoses.- - - - - - - - - - ranking = 0.021639659044986keywords = storage, enzyme (Clic here for more details about this article) |
6/26. Deficiency of arylsulfatase B in 2 brothers aged 40 and 38 years (Maroteaux-Lamy syndrome, type B).Two brothers, aged 40 and 38 years, suffered from dysplastic features, coarse facies, bone and skeletal abnormalities, deformities of spine, and joint impairments. Body heights were 168 and 164 cm, respectively. Enlargement of liver and spleen, cardiac insufficiency, marked corneal clouding, and hernias were absent. Both patients had signs of cervical and lumbar radiculopathy and cervical myelopathy (tetraspastic syndrome). vacuoles, acid phosphatase-positive granules, and metachromatic inclusions were found in peripheral lymphocytes; granulocytes and monocytes contained azurophilic hypergranulation. By electron microscopy, clear membrane-bound vacuoles were noted in lymphocytes (but not in neurtrophils), fibroblasts, schwann cells, mural cells of the vasculature, and epidermal cells. leukocytes, urine, and cultured skin fibroblasts revealed a deficiency of arylsulfatase B (N-acetylgalactosamine 4-sulfate sulfatase). The 6-year-old daughter of one of the patients has an intermediate level of this enzyme. fibroblasts exhibited a constant intracellular accumulation of 35S-labeled mucopolysaccharides. The urine of one of the brothers showed an abnormal mucopolysacchariduria; in both, the presence of urinary dermatan sulfate could be demonstrated. These findings conform to the mild B variant of Maroteaux-Lamy syndrome with high longevity.- - - - - - - - - - ranking = 0.0025725982417464keywords = enzyme (Clic here for more details about this article) |
7/26. An n-acetylgalactosamine-4-sulfatase mutation (delta G238) results in a severe Maroteaux-Lamy phenotype.Maroteaux-Lamy syndrome (mucopolysaccharidosis type VI, MPS VI) is an autosomally inherited lysosomal storage disorder caused by a deficiency of n-acetylgalactosamine-4-sulfatase (EC 3.1.6.1; 4-sulfatase). In order to determine the gene defect in a clinically severe MPS VI patient, polymerase chain reaction (PCR) products were generated from the patient's fibroblast mRNA and also from a 4-sulfatase cDNA clone and subjected to the chemical cleavage technique to detect mismatched bases, which were then identified by direct dna sequencing of the PCR products. The patient was homozygous for an early frameshift mutation caused by the deletion of a G at position 238 (delta G238), which produces a truncated 4-sulfatase with an altered amino acid sequence from amino acid 80 to a premature stop codon at codon 113 relative to the normal 4-sulfatase reading frame of 533 amino acids. Since the mutation occurs only 40 amino acids past the signal peptidase cleavage site, it is most likely that this will result in a protein with no 4-sulfatase activity. This is consistent with the severe clinical presentation and the absence of 4-sulfatase enzyme activity or mutant 4-sulfatase protein in the patient. The patient was also found to be homozygous for two polymorphisms, i.e., a G to A transition at nucleotide 1072 resulting in a valine358 to methionine substitution (V358M) and a salient A to G transition in the third base of the proline397 codon at nucleotide 1191.- - - - - - - - - - ranking = 1.9126406256916keywords = lysosomal storage, storage, enzyme (Clic here for more details about this article) |
8/26. early diagnosis of Maroteaux-Lamy syndrome in two patients with accelerated growth and advanced bone maturation.The diagnosis of mucopolysaccharidosis (MPS) VI is usually not made before the age of 2 or 3 years when the main clinical signs of dwarfed stature, skeletal deformities, coarsening facies, stiff joints and hepatosplenomegaly described in textbooks are recognisable. Conversely, accelerated growth with advanced bone age, a precocious feature of this condition although not suggestive of a storage disorder, is usually neither recognised, nor adequately interpreted. We report on two infants with MPS VI who presented with these two "unexpected" features within the 1st year of life. CONCLUSION: Recognition of precocious excessive growth in a mucopolysaccharidosis enables an early diagnosis, the prime responsibility of the clinician, in order to propose early treatment like bone marrow transplantation or active recombinant sulphatase therapy, and appropriate genetic counselling.- - - - - - - - - - ranking = 0.01906706080324keywords = storage (Clic here for more details about this article) |
9/26. Maroteaux-Lamy syndrome.mucopolysaccharidoses are a type of lysosomal storage disorders characterized by defect in the degradation of Mucopolysaccharides due to deficiency of specific lysosomal enzymes leading to their accumulation in various tissues. MPS -VI (Maroteaux-Lamy syndrome) is an autosomal recessive syndrome due to deficiency of enzyme Aryl- Sulfatase -B, and is characterized by characteristic facies, normal intelligence, Dysostosis multiplex, organomegaly, joint stiffness, corneal clouding and striking inclusions in peripheral blood leucocytes. We present an 8-year-old male child with MPS-VI syndrome, confirmed by enzyme assay.- - - - - - - - - - ranking = 2.9152132239334keywords = lysosomal storage, lysosomal enzyme, storage, enzyme (Clic here for more details about this article) |
10/26. An index case for the attenuated end of the mucopolysaccharidosis type VI clinical spectrum.Mucopolysaccharidosis type VI (MPS VI, Maroteaux-Lamy syndrome, McKusick #253200) is a lysosomal storage disorder that is caused by a deficiency in the lysosomal exohydrolase N-acetylgalactosamine-4-sulphatase (4-sulphatase, EC 3.1.6.1). We report a patient with no obvious clinical signs of MPS VI that has 5% of normal 4-sulphatase catalytic capacity. This patient represents an index case for the attenuated end of the MPS VI clinical spectrum.- - - - - - - - - - ranking = 1.9100680274499keywords = lysosomal storage, storage (Clic here for more details about this article) |
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