1/59. 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. ( info) |
2/59. 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. ( info) |
3/59. 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. ( info) |
4/59. Neurosurgical interventions in children with Maroteaux-Lamy syndrome. Case report and review of the literature. This paper reports the case of a 14-year-old child with Maroteaux-Lamy syndrome (mucopolysaccharidosis type 6) who was treated consecutively for compressive damage of the optic nerves, hydrocephalus communicans and progressive spastic tetraparesis within 2 years. The clinical course of the patient is presented and the pathophysiologic mechanisms of disease progression in patients with Maroteaux-Lamy syndrome are discussed and reviewed. ( info) |
| PURPOSE: To present a case of Maroteaux-Lamy syndrome (MLS, mucopolysaccharidosis [MPS] type VI) who underwent bone marrow transplantation (BMT) for gene transfer at the age of 13, and penetrating keratoplasty at the age of 17, and maintained clear corneal grafts bilaterally for 13 years. To our knowledge, this is the longest follow-up reported on corneal graft survival in a patient with MLS and BMT. methods: In 1982, BMT was successfully performed on a 13-year-old girl with MLS with growth retardation, typical facial features, skeletal and joint deformities, hepatosplenomegaly, cardiopulmonary dysfunction, and corneal clouding. corneal transplantation was done on the left eye in 1986, and on the right eye in 1987 (6 months later) without difficulty or complication. RESULTS: Thirteen years postoperatively, the patient was systemically well, and both eyes retained clear corneal grafts. CONCLUSION: BMT retarded further dysfunction from MLS, and the corneal transplants retained clarity. Further controlled studies with longer follow-up are required to establish the efficacy of BMT in ocular manifestations of MPS or MLS. ( info) |
6/59. 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. ( info) |
7/59. Clinical and morphological features including expression of betaig-h3 and keratan sulphate proteoglycans in Maroteaux-Lamy syndrome type B and in normal cornea. AIM: To carry out a detailed morphological study of the cornea of a 16 year old female with a Maroteaux-Lamy syndrome (MLS). methods: Following a penetrating keratoplasty in July 1999, ultrastructural changes in the cornea were examined using electron microscopy. proteoglycans were visualised using cuprolinic blue dye; and betaig-h3 and keratan sulphate were detected by immunoelectron microscopy. RESULTS: The epithelial cells were degenerate and contained apoptotic nuclei. proteoglycans were present in epithelial cells, intercellular spaces, and in swollen desmosomes. An abnormally large quantity of proteoglycans was present throughout the stroma. Keratocytes throughout the stroma had no cell organelles, were vacuolated, and contained a large quantity of abnormal proteoglycans. Labelling for betaig-h3 was intense around electron lucent spaces in stroma. No labelling was seen in keratocytes or endothelial cells. In normal cornea, keratan sulphate labelling was regular throughout the stroma. In MLS VI type B cornea, keratan sulphate labelling was weak in the anterior stroma but very intense in the posterior stroma and in keratocyte lysosomes and vacuoles. CONCLUSION: A deficiency of aryl sulfatase B results in the deposition of keratan sulphate proteoglycan and other proteoglycans in lysosomes, causing the death of keratocytes and an abnormal build-up of proteoglycans in the stroma. This might be responsible for the lateral aggregation of collagen fibrils and impaired fibrillogenesis in MLS VI. Degenerate swollen keratocytes, together with gross changes in epithelial, stromal, and endothelial cells, would be expected to increase light scattering significantly in these corneas. ( info) |
8/59. 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. ( info) |
| We report a 28-month-old male child, known to have Maroteaux-Lamy syndrome (mucopolysaccharidosis type VI), who presented with inconsistent right hand discomfort. Clinical suspicion of right carpal tunnel syndrome was confirmed by nerve conduction and electromyographic studies, and a decompressive procedure was done with uneventful recovery. carpal tunnel syndrome in mucopolysaccharidosis patients should be suspected, diagnosed and treated early for better outcome. ( info) |
10/59. 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. ( info) |