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Hurler's disease.

Hurler's disease, also known as mucopolysaccharidoses 1H, an autosomal recessive disease due to enzyme alpha-iduronidase deficiency has generally a spectrum of findings involving the eye, skeletal abnormality, organomegaly, joint stiffness, hernia, mental retardation and cardiovascular abnormalities. The two cases presented here are related to each other as brother of 9 years age and sister of 7 years of age with their parents had consanguineous marriage. On ocular examination in both the cases there was dense bilateral corneal opacities. Glycosaminoglycan's level was found to be 4 mg/mmol cr in the first case and 5 mg/mmol cr in the second case. In the first case no ocular treatment was planned and in the second case penetrating keratoplasty was the choice of management.

Child↗

The molecular basis of mucopolysaccharidosis type I in two Thai patients.

Two Thai patients diagnosed with Hurler syndrome (mucopolysaccharidosis type 1, MPS I) were found to have no detectable alpha-iduronidase (E.C. 3.2.1.76) activity in leukocytes, while normal Thai children all had significant activity, with a mean of 135 +/- 30 nmol/mg/18h. One patient was heterozygous for A75T (311G>A) and S633L (1986C>T) mutation, previously reported to cause MPS I, together with 9 other heterozygous polymorphisms also found in normal controls. The other patient had the previously described frameshift mutation 252insert C and a new nonsense mutation E299X (983G>T).

Base Sequence↗

Attenuated type I mucopolysaccharidosis in the differential diagnosis of juvenile idiopathic arthritis: a series of 13 patients with Scheie syndrome.

OBJECTIVE: Mucopolysaccharidosis type I (MPS I) is a genetic lysosomal storage disorder caused by deficient activity of the enzyme alpha-L-iduronidase. Incomplete breakdown of glycosaminoglycans leads to progressive accumulation of these substances in many tissues throughout the body. Patients with the less severe form of MPS I (Scheie syndrome) usually present in the first decade of life with frequent articular involvement, and may survive into adulthood. Especially in these attenuated phenotypes, a definitive diagnosis may be delayed for years because clusters of early symptoms are difficult to recognize for physicians not familiar with the disease, and since the disease progresses slowly over decades. We would like to increase the awareness of this type of MPS I disease among rheumatologists and unravel diagnostic pitfalls. METHODS: We have reviewed medical histories of 13 patients (6 males and 7 females) with Scheie syndrome seen in 5 European centers. RESULTS: All patients had prominent musculoskeletal involvement at the onset of their disease in childhood. Diagnosis was delayed in almost all cases (range 4-54 years). CONCLUSION: We suggest that patients who present with progressive non-inflammatory joint involvement in the first decade of life, particularly with stiffness of the fingers and difficulty using the hands, should be screened for metabolic diseases, including MPS I. MPS I should be considered if patients with arthropathy lack the typical characteristics of inflammatory arthropathy.

Arthritis, Juvenile↗

Hurler syndrome with special reference to histologic abnormalities of the growth plate.

Hurler syndrome is a mucopolysaccharide disorder resulting from an heritable deficiency in alpha-L-iduronidase, an enzyme required in the catabolism of heparan sulfate and dermatan sulfate glycosaminoglycan (GAGs). The resultant intracellular accumulation of GAG leads to disruption of the intracellular and extracellular environment and dysfunction of multiple organ systems. Among the most noted manifestations of this disease is disproportionate short trunk dwarfism, which develops during the first years of life. Histochemical and electron-microscopic observations on a 30-month-old child with Hurler syndrome showed marked irregularities in chondrocyte orientation within the growth plate, along with disruption of the normal columnar architecture. Vacuolization with enlargement of the cellular border was the characteristic ultrastructural finding. An heritable abnormality in the enzymatic degradation of structural glycosaminoglycans leads to profound disruption of the normal mechanisms of growth and development.

Cartilage↗

Corneal opacity in canine MPS I. Changes after bone marrow transplantation.

Corneal opacification associated with glycosaminoglycan (GAG) deposition occurs in canine mucopolysaccharidosis I (MPS I), a deficiency of the lysosomal enzyme alpha-L-iduronidase. In affected dogs corneal lesions appear similar to those in children with the same disease. Transplantation of bone marrow from unaffected littermates was performed in 5 MPS I affected dogs at 5 months of age. In three recipients that became long-term survivors corneal clouding was largely alleviated compared to affected control dogs. In no case, however, did the corneas remain totally clear throughout the course of the study (594, 628 and 1425 days). Light and electron microscopic findings correlated with the clinical impression of partial improvement. Glycosaminoglycan analysis of corneal tissue from two transplant recipients, one normal littermate, and one MPS I-affected, untransplanted dog showed quantitative and qualitative changes in stored GAG following bone marrow transplantation.

Animals↗

[Changes in the activities of lysosomal enzyme (glycosidase) in experimental acute gastric mucosal lesion].

In order to study the pathogenesis of stress-induced ulcer, we induced experimental acute gastric mucosal lesion (AGML) by loading the rats with heat-burn stress, and we monitored the activities of four glycosidases having mucolytic action. The activity of beta-N-Acetyl-D-glucosaminidase was 59.50 +/- 3.27 micrograms 4 MU/h/mg protein before stress, increasing significantly one to three hours after burn, and that of beta-N-Acetyl-D-galactosaminidase was 17.50 +/- 1.60 micrograms 4 MU/h/mg protein before stress, increasing significantly two hours after burn. The activities of two uronic acid exoglycosidases, alpha-L-Iduronidase and beta-D-Glucuronidase were 4.52 +/- 0.37 and 8.68 +/- 0.89 micrograms phenol/h/mg protein before stress; both increased significantly one to three hours after burn. Burn stress caused microcirculatory disturbance in the gastric mucosa, release of histamine and other vasoactive substances, and accelerated release of lysosomal enzymes. Triggered by these reaction, glycosidases were released to cause the degradation of glycoprotein in the tissue and resulted in the breakdown of the defense mechanisms.

Acute Disease↗

[Psychotic symptoms during the evolution of dementia in muco- polysaccharidosis of Hurler-Scheie phenotype].

The case reported concerns a 17 1/2 year-old adolescent presenting with complete alpha-L-iduronidase deficiency. Its phenotype intermediate between Hurler's and Scheie's syndromes and the occurrence of a delirious and hallucinatory condition evolving with acute exacerbations on a constant subdelirious and excited state made this case particular. This case report is compared to the 30 in the Anglo-Saxon literature which shows, in addition to the rarity of psychiatric symptoms (one single case), the multiplicity of the possible phenotypes, reinforcing the hypothesis of a polyallelic or even non allelic mutation.

Adolescent↗

Antenatal diagnosis of Hurler's syndrome.

Hurler's syndrome was diagnosed antenatally in the two consecutive pregnancies of a mother with one affected child. In both instances, diagnosis was based upon a demonstration of the presence of unusual glycosaminoglycan components in the amniotic fluid, of abnormal metabolic activity in cultured amniotic fluid cells, and a deficiency of the lysosomal enzyme alpha-L-iduronidase in these cell homogenates. Bothe pregnancies were terminated before the 24th week and the diagnosis was confirmed by biochemical studies of the fetal livers.

Amniotic Fluid↗

Coated vesicles from rat liver and calf brain contain lysosomal enzymes bound to mannose 6-phosphate receptors.

Coated vesicles from calf brain and rat liver contain cryptic receptors which recognize and bind lysosomal enzymes via mannose 6-phosphate residues on oligosaccharide side chains (Campbell, C. H., Fine, R. E., Squicciarini, J., and Rome, L. H. (1983) J. Biol. Chem. 258, 2628-2633). In addition to mannose 6-phosphate receptors, we now report that coated vesicles from calf brain and rat liver contain the lysosomal enzymes alpha-L-fucosidase, beta-galactosidase, beta-glucosidase, beta-hexosaminidase, alpha-L-iduronidase, and alpha-mannosidase. Enzyme activities co-migrated with coated vesicles purified by agarose gel electrophoresis. Treatment of intact coated vesicles with pronase (0.05 mg/ml) had little effect on lysosomal enzyme activities, whereas a similar treatment of coated vesicles in the presence of 0.045% taurodeoxycholate resulted in the loss of most of the enzyme activities. Addition of 10 mM mannose 6-phosphate to disrupted liver coated vesicles specifically displaced up to 80% of the cryptic lysosomal enzyme activity. Disrupted liver coated vesicles and highly purified liver lysosomes were treated with anti-beta-hexosaminidase A and anti-beta-galactosidase antibodies and immunoprecipitates were analyzed by polyacrylamide gel electrophoresis. High molecular weight bands were present in the coated vesicle immunoprecipitates which were not present in the lysosome immunoprecipitates. The data suggest that coated vesicles contain mannose 6-phosphate receptor-bound lysosomal enzymes, some of which are of a higher molecular weight form. These higher molecular weight forms may represent newly synthesized enzymes that are en route to lysosomes.

Animals↗

The pathology of the feline model of mucopolysaccharidosis I.

Five cats with feline alpha-L-iduronidase-deficient mucopolysaccharidosis were studied. Membrane-bound cytoplasmic inclusions were present in central nervous system neurons, hepatocytes, chondrocytes, vascular and splenic smooth muscle cells, bone marrow leukocytes, and fibroblasts of the skin, eye, and cardiac valves. The lesions in these cats closely resemble those described in human patients with mucopolysaccharidosis I H (Hurler syndrome).

Animals↗

[Echocardiographic findings in 3 cases of mucopolysaccharidosis].

Mucopolysaccharidosis (MPS) has been shown to cause cardiac involvements. However, echocardiographic features of MPS were not well understood. We examined echocardiographic findings in three adult patients with MPS. The diagnosis was confirmed by measuring urinary acid mucopolysaccharide and alpha-L-iduronidase activity in the white blood cell and skin fibroblast. The age ranged from 29 to 54 years. Two patients were Scheie syndrome (MPS I-S) and one was suspected to be Maroteaux-Lamy syndrome (MPS VI). All patients had a systolic heart murmur suggestive of aortic stenosis, and one had an additional apical systolic murmur consistent with mitral regurgitation. The echocardiogram revealed the following findings; 1) an abnormal thickening of all aortic leaflets with reduced valve opening in all cases, 2) diffuse and marked thickening of the mitral leaflets, chordae and papillary muscles, no upward motion of the posterior mitral leaflet in spite of reduced E-F slope (13, 23 and 17 mm/sec, respectively), and slight narrowing of the mitral orifice, and 3) a slightly thickened and dilated left ventricle (IVS: 11, PW: 12, EDd: 58, and ESd 44 mm) in the case with Maroteaux-Lamy syndrome. The last finding was probably due to deposition of mucopolysaccharide in the myocardium, because the coronary arteriogram in this case did not demonstrate any significant lesions. The echocardiographic characteristics in our adult MPS cases were similar to those reported in infant or juvenile cases with Hurler syndrome (MPS 1-H) or Hunter syndrome (MPS II). However, our Maroteaux-Lamy patient may be the first case, in which myocardial involvement by mucopolysaccharide was suggested echocardiographically.

Adult↗

Effect of bacterial endotoxin on lysosomal enzyme activities of normal and mucolipidosis III fibroblasts.

The effect of bacterial endotoxin (LPS) on lysosomal enzyme activities of fibroblasts from normals and mucolipidosis III patients was investigated. Exposure of normal fibroblasts to LPS for 24 hours resulted in enhanced intracellular activities of beta-glucuronidase, beta-galactosidase, alpha-L-iduronidase and beta-N-acetylglucosaminidase. Endotoxin also led to an increased extracellular activity of beta-N-acetylglucosaminidase. In contrast, mucolipidosis III fibroblasts did not show either intracellular or extracellular increase of lysosomal hydrolases after LPS treatment. Difference in cellular responsiveness to LPS may be related to the mechanism of LPS-cell interaction.

Endotoxins↗

Craniofacial abnormalities in animal models of mucopolysaccharidoses I, VI, and VII.

The genetic mucopolysaccharidoses (MPS) are a family of lysosomal storage diseases resulting from the partial catabolism of several glycosaminoglycans (GAGs). Depending on the particular enzyme deficient in activity, the MPS syndromes are defined into groups MPS I through VII, with several subgroups for a total of 10 disorders. In humans, clinical features include dysostosis multiplex, hepatosplenomegaly, hypertelorism, macroglossia, hypoplastic and irregularly shaped teeth, hyperplastic lips and gingiva, facial dysmorphia, corneal clouding, and mental retardation. MPS I (alpha-L-iduronidase deficiency) and VI (arylsulfatase B deficiency) have been described in cats, MPS VII (beta-glucuronidase deficiency) in dogs. Biochemically, these syndromes appear the same as their human counterparts and have similar clinical characteristics. All are inherited as autosomal recessive traits. The purpose of this study was to analyze the craniofacial aspects of these diseases in the animal models and compare these data with descriptions of the human syndromes. A total of 28 live animals were examined. Thirty-one skulls prepared from postmortem specimens were measured directly and radiographed. Controls were closely related family members of the same sex and similar age without the disease, clinically or biochemically. The data indicated that, as in the human syndromes, each is distinct, and the skull bones most severely affected are those of endochondral origin.

Animals↗

Regulation of lysosomal sulfate transport by thyroid hormone.

Sulfate transport was examined in rat liver lysosomes that were isolated from thyroid hormone-treated, thyroidectomized, and control animals. Sulfate uptake was significantly decreased in lysosomes from animals that had received intraperitoneal T3 (3,5,3'-triiodothyronine) at a dose of 20 micrograms/100 g body weight. The effect of T3 was maximal by 24 h post-injection and resulted in marked decreases in both Vmax (control: 155 +/- 33 pmol/unit of beta-hexosaminidase/30 s versus T3 treated: 24 +/- 7 pmol/unit of beta-hexosaminidase/30 s) and Km (control: 213 +/- 34 microM versus T3 treated: 92 +/- 6 microM). Thyroidectomy was associated with a significant increase in Vmax (control: 250 pmol/unit of beta-hexosaminidase/30 s versus thyroidectomized: 564 pmol/unit of beta-hexosaminidase/30 s), while Km was not significantly affected. The effect of thyroid hormone on lysosomal sulfate transport appeared to be relatively specific. In contrast to its effect on sulfate transport, T3 treatment had no effect on the uptake of either glucose or N-acetylglucosamine by rat liver lysosomes. Lysosomal pH, acidification in response to Mg/ATP, and the specific activities of alpha-L-iduronidase, beta-hexosaminidase, beta-D-glucosidase, and acid phosphatase were unaffected by T3 administration. Incubation of T3 with lysosomes from control animals had little or no effect on sulfate transport. Treatment of isolated lysosomes with either protein kinase A or alkaline phosphatase resulted in modest stimulation of transport. Thus, T3 does not appear to regulate transport by either direct interaction with the lysosomal transporter or protein kinase A-mediated phosphorylation. The exact mechanism for the inhibitory effect of T3 on lysosomal sulfate transport remains to be determined.

Animals↗

[Mucopolysaccharidosis type I, Hurler-Scheie phenotype with ocular involvement. Clinical and ultrastructural study].

The authors report the case of a 37 year-old male who presented with type I Hurler-Scheie (H-S) mucopolysaccharidosis revealed by ocular complications including bilateral corneal opacification and glaucoma. These complications are identical to those seen in Scheie's mucopolysaccharidosis. The patient underwent a trabeculectomy and a penetrating keratoplasty in both eyes. The corneal storage material was shown on the histological and ultrastructural examination of the buttons. These ocular complications result from excessive tissular storage of acid mucopolysaccharides due to an enzymatic alpha-L-iduronidase deficiency which was proved in our patient. H-S mucopolysaccharidosis is also characterized by dysmorphia and altered intellectual functions like in Hurler's disease in which the prognosis is however. The characteristics of the disease are discussed as well as the different therapeutical strategies which rely on leucocyte injections, skin fibroblast or bone marrow transplantation.

Conjunctiva↗

[Fetal pathology in Fabry's disease and mucopolysaccharidosis type I].

Fetal Fabry disease (defect of alfa galactosidase) and mucopolysaccharidosis I (defect of alfa iduronidase, family with IH phenotype) were diagnosed by biochemistry in two risk gravidities subsequently interrupted according to mother's demand. Fetus with Fabry disease (gestation age 19 weeks) had rudimentary storage in kidney and myenteric plexuses cells, cardiocytes were normal. Biopsy of chorionic villi showed a bit more conspicuous storage in single trophoblastic elements. Much more striking storage was observed in MPS I (gestational age 14-15 weeks) especially in liver (hepatocytes and sinus cells), spleen (sinus endothelial cells and pulp macrophages) and fibroblasts of skin and placenta. Skin peripheral nerves and cerebral cortical gangliocytes did not show any lysosomal storage. Different manifestation of storage in fetal age may reflex the speed of lysosomal storage development in both lysosomal enzymopathies.

Fabry Disease↗