1/51. Mutations in HYAL1, a member of a tandemly distributed multigene family encoding disparate hyaluronidase activities, cause a newly described lysosomal disorder, mucopolysaccharidosis IX.Hyaluronan (HA), a large glycosaminoglycan abundant in the extracellular matrix, is important in cell migration during embryonic development, cellular proliferation, and differentiation and has a structural role in connective tissues. The turnover of HA requires endoglycosidic breakdown by lysosomal hyaluronidase, and a congenital deficiency of hyaluronidase has been thought to be incompatible with life. However, a patient with a deficiency of serum hyaluronidase, now designated as mucopolysaccharidosis IX, was recently described. This patient had a surprisingly mild clinical phenotype, including notable periarticular soft tissue masses, mild short stature, an absence of neurological or visceral involvement, and histological and ultrastructural evidence of a lysosomal storage disease. To determine the molecular basis of mucopolysaccharidosis IX, we analyzed two candidate genes tandemly distributed on human chromosome 3p21.3 and encoding proteins with homology to a sperm protein with hyaluronidase activity. These genes, HYAL1 and HYAL2, encode two distinct lysosomal hyaluronidases with different substrate specificities. We identified two mutations in the HYAL1 alleles of the patient, a 1412G --> A mutation that introduces a nonconservative amino acid substitution (Glu268Lys) in a putative active site residue and a complex intragenic rearrangement, 1361del37ins14, that results in a premature termination codon. We further show that these two hyaluronidase genes, as well as a third recently discovered adjacent hyaluronidase gene, HYAL3, have markedly different tissue expression patterns, consistent with differing roles in HA metabolism. These data provide an explanation for the unexpectedly mild phenotype in mucopolysaccharidosis IX and predict the existence of other hyaluronidase deficiency disorders.- - - - - - - - - - ranking = 1keywords = lysosomal storage, storage disease, storage (Clic here for more details about this article) |
2/51. chondroitin 4- and 6-sulfate mucopolysaccharidosis--a morphological study.A 17-year-old patient clinically manifesting gargoyle face, dwarfism, skeletal bone deformity, mild mental retardation and benign course was presented. Biochemically, increased urinary excretion of acidic glycosaminoglycans was confirmed and chondroitin 4-sulfate and chondroitin 6-sulfate were substantiated to be the major components of the acid mucopolysacchariduria. light microscopically, variable numbers of foam cells were observed in the biopsy materials of the lymph nodes, liver and skin, as well as in the smears of bone marrow aspirates. In the liver, the parenchymal cells appeared vacuolated. Histochemically, accumulation of sulfated acid glycosaminoglycans was demonstrated in the cytoplasm of the foam cells proliferating in these tissues, as well as in the liver cells. Electron microscopically, all of these storage cells were found to contain numerous, membrane-bound, vacuolar inclusions filled with flocculent, finely reticulogranular materials of low electron density similar to those seen in the storage cells of Hurler, Hunter or Sanfilippo's syndrome. Empty vacuoles were often coexistent. Accordingly, this case should be termed "chondroitin 4- and 6-sulfate mucopolysaccharidosis", with emphasis on the possibility of a new type of genetic mucopolysaccharidosis.- - - - - - - - - - ranking = 0.079479992562991keywords = storage (Clic here for more details about this article) |
3/51. Sanfilippo type C disease: clinical findings in four patients with a new variant of mucopolysaccharidosis iii.A new genetic variant of the Sanfilippo syndrome due to deficiency of acetyl CoA: alpha-glucosaminide N-acetyltransferase, was recently demonstrated in four patients. The clinical findings of these patients are reported here. Differential diagnosis from other types of the Sanfilippo syndrome on clinical and routine laboratory criteria is difficult and enzyme assay is necessary to reach the diagnosis. Since two of the patients reported are females and consanguinity was present in one case, autosomal recessive inheritance is most probable.- - - - - - - - - - ranking = 0.0021060662085275keywords = enzyme (Clic here for more details about this article) |
4/51. Treatment of mucopolysaccharidosis: clinical and biochemical aspects of leucocyte transfusion as compared with plasma infusion in patients with Hurler's and Scheie's syndromes.The therapeutic effectiveness of leucocyte transfusion (LT) was compared with that of plasma infusion (PI) clinically by range of motion (ROM) of joints and biochemically from the standpoint of alpha-L-iduronidase activity and urinary excretion of acid mucopolysaccharides (AMPS) in 2 patients with Hurler's and Scheie's syndromes. Both syndromes are considered to be due to the lack of alpha-L-iduronidase activity, a congenital metabolic disorder. As a result, leukocyte transfusion surpasses plasma infusion with respect to enzyme content, the grade and duration of clinical improvement in the stiffness of joints. Clinical improvement in the stiffness of joints was correlated with the degradation of AMPS when the ratio of urinary AMPS fragments to the total large molecule AMPS has become 50% or more after the leucocyte transfusion and plasma infusion.- - - - - - - - - - ranking = 0.0021060662085275keywords = enzyme (Clic here for more details about this article) |
5/51. Mucopolysaccharidosis in a domestic short-haired cat--a disease distinct from that seen in the Siamese cat.A 10-month-old male domestic short-haired cat was examined because of progressive lameness, a broad face with depressed nasal bridge, small ears, corneal clouding, and multiple bone dysplasia. The cat excreted excessive amounts of glycosaminoglycan (a component of connective tissue) in its urine and had evidence of lysosomal storage of glycosaminoglycans in fibroblasts and neurons. Activity of alpha-L-iduronidase, a lysosomal enzyme involved in glycosaminoglycan degradation, was deficient in cultured fibroblasts and leukocytes. The mucopolysaccharidosis was distinct from that seen in Siamese cats in terms of the pathologic changes and the specific enzyme deficiency.- - - - - - - - - - ranking = 5.9719635107461keywords = lysosomal enzyme, lysosomal storage, storage, enzyme (Clic here for more details about this article) |
6/51. Morquio-B syndrome (MPS-IV B) associated with beta-galactosidase deficiency in two siblings.In the present article we describe two cases with Morquio-B syndrome characterized by beta-galactosidase deficiency in a Muslim family. They were found to have skeletal dysplasia, short stature and short trunk dwarfism with undetectable level of beta-galactosidase in leucocytes. Probands' sister who had no clinical signs of mucopolysaccharidosis was investigated and found to have normal levels of the enzyme. Mother was found to have a deficient activity of beta-galactosidase and father was not available for the study. Since mother was pregnant, prenatal study from chorionic cells was carried out to investigate beta-galactosidase activity in the chorionic villus. An intermediate level of beta-galactosidase activity was found in the chorionic villus cells suggesting a carrier status. The diversity and rarity of the study makes it worth presenting.- - - - - - - - - - ranking = 0.0021060662085275keywords = enzyme (Clic here for more details about this article) |
7/51. 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 = 0.041846062490023keywords = storage, enzyme (Clic here for more details about this article) |
8/51. 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 = 0.0021060662085275keywords = enzyme (Clic here for more details about this article) |
9/51. Winchester syndrome. A case report and literature review.The mucopolysaccharidoses are a group of inherited lysosomal storage diseases that are caused by a deficiency of specific enzymes. The acid mucopolysaccharides are stored in tissue and excreted in large quantities in the urine. The storage of this material leads to effects on a wide variety of tissues and to remarkable changes in morphologic features. Winchester syndrome is a rare disorder in the group of mucopolysaccharidoses. This article is a report of a case with classic clinical, radiologic, and biochemical characteristics of the Winchester syndrome.- - - - - - - - - - ranking = 1.04184606249keywords = lysosomal storage, storage disease, storage, enzyme (Clic here for more details about this article) |
10/51. Beta-glucuronidase deficiency in a girl with unusual clinical features.beta-glucuronidase deficiency in fibroblasts, leucocytes and in serum and increased urinary excretion of mucopolysaccharides were found in a girl, now 13 years old, who exhibits some features of a mucopolysaccharidosis such as moderate mental deficiency, craniofacial dysmorphism, a short neck, protruding sternum, vertebral deformities and corneal clouding. Coarse granulations were found in her leucocytes. The liver and spleen are not enlarged and there is no gingival hyperplasia. Additional features, hitherto undescribed, are hydronephrosis and defective ossification of the medial carpal and tarsal bones. Low enzyme activity in the parents and a normal brother suggests heterozygosity.- - - - - - - - - - ranking = 0.0021060662085275keywords = enzyme (Clic here for more details about this article) |
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