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At least 343 records · Page 19Linked to original sources

Sleep apnoea in Scheie's syndrome.

An 18-year-old student presented with a two-year history of daytime sleepiness and noisy breathing during sleep. Both he and his brother, aged 25 years, had Scheie's syndrome, a mucopolysaccharidosis characterised by small stature, micrognathia, corneal clouding, hepatosplenomegaly, raised urinary mucopolysaccharides, and undetectable levels of alpha-L-iduronidase assayed in cultured fibroblasts. Both brothers had sleep apnoea (apnoea index, 59 and 35 respectively) during which there was a significant fall in heart rate and arterial oxygen saturation. One brother had EEG changes suggestive of cerebral hypoxia and the other had ventricular extrasystoles at the end of several episodes. Tracheostomy in the younger brother produced a dramatic symptomatic improvement and reduced the number and severity of apnoeic episodes (post-tracheostomy apnoea index 2.4).

Adolescent↗

Hurler/Scheie phenotype. Report of an inbred sibship with tapeto-retinal degeneration and electron-microscopie examination of the conjuctiva.

An inbred sibship with corneal opacities and deficient alpha-L-iduronidase activity showed signs of a Hurler/Scheie phenotype. The children were of normal intelligence. In one of the children, electron microscopy of the conjunctiva showed membrane-bound intracellular vacuoles and the electroretinogram was extinguished. The consanguinity of the parents is taken to indicate the presence of homozygosity of a mutant gene different from both the Hurler and Scheie mutants, thus rejecting the concept of a genetic compound in our patients.

Child↗

Heterogenous zonal distribution of lysosomal enzymes in rat liver.

The activities of beta-N-acetylglucosaminidase, beta-glucuronidase, alpha-L-iduronidase and acid phosphatase were all significantly higher in the cell lysates from the periportal than from the perivenous region obtained by the regioselective digitonin treatment of the perfused liver. The activities of cathepsins B, H and L were only slightly higher in the periportal than in the perivenous cell lysates. These results support the view that there is little zonation of lysosomal degradation of proteins, whereas the enzymatic capacity for degradation of glycosaminoglycans may be more active in the periportal region.

Acid Phosphatase↗

Functional abnormalities of heparan sulfate in mucopolysaccharidosis-I are associated with defective biologic activity of FGF-2 on human multipotent progenitor cells.

In mucopolysaccharidosis-I (MPS-I), alpha-L-iduronidase deficiency leads to progressive heparan sulfate (HS) and dermatan sulfate (DS) glycosaminoglycan (GAG) accumulation. The functional consequences of these accumulated molecules are unknown. HS critically influences tissue morphogenesis by binding to and modulating the activity of several cytokines (eg, fibroblast growth factors [FGFs]) involved in developmental patterning. We recently isolated a multipotent progenitor cell from postnatal human bone marrow, which differentiates into cells of all 3 embryonic lineages. The availability of multipotent progenitor cells from healthy volunteers and patients with MPS-I (Hurler syndrome) provides a unique opportunity to directly examine the functional effects of abnormal HS on cytokine-mediated stem-cell proliferation and survival. We demonstrate here that abnormally sulfated HS in Hurler multipotent progenitor cells perturb critical FGF-2-FGFR1-HS interactions, resulting in defective FGF-2-induced proliferation and survival of Hurler multipotent progenitor cells. Both the mitogenic and survival-promoting activities of FGF-2 were restored by substitution of Hurler HS by normal HS. This perturbation of critical HS-cytokine receptor interactions may represent a mechanism by which accumulated HS contributes to the developmental pathophysiology of Hurler syndrome. Similar mechanisms may operate in the pathogenesis of other diseases where structurally abnormal GAGs accumulate.

Case-Control Studies↗

Atypical microbial infections of digestive tract may contribute to diarrhea in mucopolysaccharidosis patients: a MPS I case study.

BACKGROUND: Mucopolysaccharidoses are heritable, metabolic diseases caused by deficiency in an activity of one of specific lysosomal enzymes involved in degradation of mucoplysaccharides (glycosaminoglycans). Among many medical problems of patients with mucopolysaccharidoses, there are frequent episodes of diarrhea of unknown etiology. CASE PRESENTATION: A girl, diagnosed enzymatically for mucopolysaccharidosis type I (deficiency of alpha-L-iduronidase) at the age of 3 years and 9 months, was investigated until the age of 5 years and 4 months. Frequent loose stools and episodes of diarrhea, often accompanied by vomiting, were encountered. Detailed microbiological analyses were performed and atypical microbial infections (most often enetropathogenic Escherichia coli, but also other species, like Pseudomonas aeruginosa or Staphylococcus aureus, as well as adenoviruses) of the digestive tract were found in most severe diarrhea episodes. Often, isolations of pathogenic bacterial strains from stools of the investigated patient suffering from diarrhea were not obvious during the first screening, and only detailed microbiological studies, including re-isolation of colonies, gave the results of isolation of particular pathogenic strains (especially in the case of enetropathogenic E. coli). CONCLUSION: We conclude that atypical microbial infections of digestive tract may contribute significantly to diarrhea in mucopolysaccaridosis patients. Since isolated strains were not typical and their isolation was often possible only after detailed investigation (not during a standard screening), such atypical microbial infections of digestive tract of mucopolysaccharidosis patients could be usually overlooked to date. Importantly, these atypical infections could be effectively treated with antimicrobial agents.

Adenoviridae Infections↗

Beta-glucuronidase deficiency in a dog: a model of human mucopolysaccharidosis VII.

This report describes a third mucopolysaccharidosis in animals: canine mucopolysaccharidosis VII. The affected dog was the offspring of a father-daughter mating. Weakness in the rear legs was evident at 8 weeks of age and became progressively worse. He had a large head, a shortened maxilla, and corneal granularities. Most joints were extremely lax, easily subluxated, with joint capsules that were swollen and fluctuant. The dog was alert and had apparently normal pain perception. At 13 months of age, there was radiographic evidence of extensive skeletal disease including bilateral femoral head luxation, abnormalities in the shape and density of the carpal and tarsal bones, radiolucent lesions of the epiphyseal regions of most long bones, and cervical vertebral dysplasia and platyspondylia. The electrophoretic pattern of precipitated glycosaminoglycans indicated a predominance of chondroitin sulfate. The animal died suddenly from gastric dilatation. There was generalized hepatomegaly, thickening of the atrioventricular heart valves, and generalized polyarthropathy. Vacuolated cytoplasm was observed in hepatocytes, keratocytes, fibroblasts, chondrocytes and cells of the synovial membrane, retinal pigment epithelium, and cardiac valves. Neurons had cytoplasmic vacuoles. Electron microscopy demonstrated membrane-bound cytoplasmic inclusions in polymorphonuclear leukocytes, hepatocytes, synovium, heart valves and spleen. The activities of 12 lysosomal hydrolases were determined in liver from the affected and control dogs: beta-glucuronidase (EC 3.2.1.31), beta-hexosaminidases A and B (EC 3.2.1.30), alpha-hexosaminidase (EC 3.2.1.-), alpha-L-iduronidase (EC 3.2.1.76), alpha-galactosidase A (EC 3.2.1.22), beta-galactosidase (EC 3.2.1.23), arylsulfatases A and B (EC 3.1.6.1), acid alpha-mannosidase (EC 3.2.1.24), acid beta-mannosidase (EC 3.2.1.25), and N-acetyl-D-galactosamine-6-sulfate sulfatase (EC 3.1.6.-).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Cardiac functional and histopathologic findings in humans and mice with mucopolysaccharidosis type I: implications for assessment of therapeutic interventions in hurler syndrome.

Hurler syndrome (mucopolysaccharidosis type I [MPS I]) is a uniformly lethal autosomal recessive storage disease caused by absence of the enzyme alpha-l-iduronidase (IDUA), which is involved in lysosomal degradation of sulfated glycosaminoglycans (GAGs). Cardiomyopathy and valvar insufficiency occur as GAGs accumulate in the myocardium, spongiosa of cardiac valves, and myointima of coronary arteries. Here we report the functional, biochemical, and morphologic cardiac findings in the MPS I mouse. We compare the cardiac functional and histopathological findings in the mouse to human MPS I. In MPS I mice, we have noted aortic insufficiency, increased left ventricular size, and decreased ventricular function. Aortic and mitral valves are thickened and the aortic root is dilated. However, murine MPS I is not identical to human MPS I. Myointimal proliferation of epicardial coronary arteries is unique to human MPS I, whereas dilation of aortic root appears unique to murine MPS I. Despite the differences between murine and human MPS I, the murine model provides reliable in vivo outcome parameters, such as thickened and insufficient aortic valves and depressed cardiac function that can be followed to assess the impact of therapeutic interventions in preclinical studies in Hurler syndrome.

Animals↗

Triplets! Unexpected structural similarity among the three enzymes that catalyze initiation and termination of thyroid hormone effects.

The three iodothyronine deiodinases catalyze the initiation (D1, D2) and termination (D3) of thyroid hormone effects in vertebrates. A recently conceived 3-dimensional model predicts that these enzymes share a similar structural organization and belong to the thioredoxin (TRX) fold superfamily. Their active center is a selenocysteine-containing pocket defined by the beta1-alpha1-beta2 motifs of the TRX fold and a domain that shares strong similarities with the active site of iduronidase, a member of the clan GH-A fold of glycoside hydrolases. While D1 and D3 are long-lived plasma membrane proteins, D2 is an endoplasmic reticulum resident protein with a half-life of only 20 min. D2 inactivation is mediated by selective UBC-7-mediated conjugation to ubiquitin, a process that is accelerated by T4 catalysis, thus maintaining local T3 homeostasis. In addition, D2 interacts with and is a substrate of the pVHL-interacting deubiquitinating enzymes (VDU1 and VDU2); thus deubiquitination regulates the supply of active thyroid hormone in D2-expressing cells.

Animals↗

Lymphoblastoid cell lines, transformed by Epstein-Barr virus, in the enzymatic study of hereditary lysosomal storage diseases.

Assay conditions were studied for eight lysosomal enzymes in lymphoblastoid cell lines transformed by Epstein-Barr virus. The transformed lymphoblastoid cells retained all eight enzyme activities, though the levels sometimes differed from those in the peripheral lymphocytes or granulocytes. The levels of these eight lysosomal enzymes were measured in lymphoblastoid cells from 11 patients with hereditary lysosomal storage diseases--GMI-gangliosidosis, a variant of beta-galactosidase deficiency (sialidase deficiency with a partial beta-galactosidase deficiency), Tay-Sachs disease, Gaucher disease, Hurler syndrome, Scheie syndrome and I-cell disease--and from 20 of their obligate heterozygotes. No activity of enzymes that were deficient in the respective disease, except I-cell disease, was detected in the lymphoblastoid cells from the patient. In I-cell disease, the cells showed lower levels of some enzyme activities. beta-D-Galactosidase activity from heterozygotes of the patient with GMI-gangliosidosis and alpha-L-iduronidase activity from heterozygotes of the patient with Hurler syndrome were in carrier range. On sephadex G-150 gel filtration, beta-D-galactosidase in control material gave two peaks (I and II). In GMI-gangliosidosis, peak II was absent and peak I was markedly diminished. Peak II in the heterozygotes was smaller than that of control. On DEAE cellulose column chromatography of hexosaminidase, two major isoenzymes (hexosaminidase A and B) were detected in control. However, hexosaminidase A was not detected in Tay-Sachs disease, and the ratios of hexosaminidase (Hex) A/Hex B in the parents were lower than those in control.

Cell Line↗

Characteristics of urinary glycosaminoglycans excreted by a patient with the Hurler-Scheie compound syndrome.

Glycosaminoglycan isolated from urine of a patient with the Hurler-Scheie compound syndrome consisted of dermatan sulfate (60%), heparan sulfate (34%) and chondroitin sulfate (6%). About 60% of both dermatan and chondroitin sulfates had molecular weight 8,000-10,000, while 95% of the heparan sulfate had molecular weight less than 6,000. The total sulfate content of the glycosaminoglycans increased with decrease in molecular weight. N-sulfate content in the heparan sulfate, however, had no relation to molecular weight, and was 0.33 mole per mole of glucosamine on the average. About 70% of the heparan sulfate with the lowest molecular weight (1,500) were composed of three repeating disaccharide units of heparan sulfate and two acetyl, one N-sulfate and three O-sulfate groups linked to the units. The dermatan sulfate contained 1.0-1.2 moles of sulfate per mole of galactosamine. Of the excess sulfate 45-65% were bound to iduronate residues and the rest to C-6 of N-acetylgalactosamine 4-sulfate residues. Most of the dermatan sulfate (83.2-100%) had nonsulfated iduronic acid at the non-reducing end. This finding is consistent with the defect of iduronidase in this disease.

Dermatan Sulfate↗

Screening study on excretion pattern of urinary glycosaminoglycans from orthopedic patients.

To obtain a clue for the metabolic disorder of glycosaminoglycans (GAG) in orthopedic diseases, a screening study on excretion pattern of urinary GAG from orthopedic patients was performed by the procedures of Nagatsuka et al. (1980). All the urines examined gave three regular GAG-bands. Besides the regular bands, some samples gave irregular bands. Of 123 cases examined in the present study, the numbers of cases with an abnormal excretion pattern of urinary GAG in the regular bands (A) and with the irregular band(s) (B) were as follows: 23(A) and 7(B) in 38 cases of rheumatoid arthritis (RA); 8(A) and 5(B) in 13 cases of malignant bone tumor; 11(A) and 3(B) in 12 cases of benign bone tumor; 16(A) and 3(B) in 25 cases of bone metabolic and connective tissue diseases; 6(A) and 4(B) in 9 cases of osteaorthritis; 6(A) and 3(B) in 8 cases of spine diseases; and 14(A) and 8(B) in 18 cases of other orthopedic diseases. The excretion patterns of urinary GAG suggested that the metabolic rates of chondroitin sulfates tended to elevate in most cases of (A). Also, certain metabolic disorder of dermatan sulfate and heparan sulfate was suggested in several cases of (A). In addition, the abnormal metabolism of acidic glycoprotein(s) was suggested in many cases of (B). Excretion of a large amount of dermatan sulfate was elucidated in one case (Case 20 of bone metabolic and connective tissue diseases) by digestion with chondroitinases after the screening study. Therefore, the metabolic disorder of dermatan sulfate was indicated in this patient. The low activity of alpha-L-iduronidase in her urine supported this indication. This patient was finally diagnosed as mucopolysaccharidosis I-S (Scheie syndrome).

Adult↗

Urinary glycosaminoglycans bearing glucuronic acid or iduronic acid residue at the reducing terminals.

The urinary glycosaminoglycan was reduced with NaB[3H]4, and was separated into three fractions according to molecular size by column chromatography on Sephadex G-200. The hexuronic acid residues at the reducing terminals of each fraction were quantified by the method of preferential quantitation of hexuronic acid at the reducing terminals. This method consisted of hydrolysis with trifluoroacetic acid and nitrous acid, lactonization, and paper chromatographic analysis. Both radioactive gulonolactone and idonolactone were detected in the fractions with a lower molecular size, but not in those with a higher molecular size. These observations demonstrated that the glucuronide and iduronide linkages at other-than-terminal sites of carbohydrate chains were cleaved by the processes of depolymerization of glycosaminoglycans in tissues. Therefore, it is highly likely that endo-beta-glucuronidase(s) and endo-alpha-iduronidase(s) which belong to the glycosidase of endo type such as hyaluronidase are involved in the catabolic degradation of glycosaminoglycans in tissues.

Carbohydrate Sequence↗

The uronidic linkages in heparitin sulfate.

Beta-glucuronidase preparations obtained from various sources were shown to liberate free D-glucuronic acid from heparitin sulfate oligosaccharides. Some free L-iduronic acid could also be detected in the hydrolyzates indicating the presence of an iduronidase in the preparations. The data presented indicate that heparitin sulfate contains a substantial amount of beta-D-glucuronidic and some alpha-L-iduronidic linkages.

Animals↗

The use of partially HLA-mismatched donors for allogeneic transplantation in patients with mucopolysaccharidosis-I.

Allogeneic bone marrow transplantation (BMT) from an HLA-matched sibling appears to improve survival and diminish some of the physiologic derangements seen in children with mucopolysaccharidosis (MPS)-I (Hurler Syndrome), an inherited metabolic storage disease resulting from the lack of alpha-L-iduronidase enzyme activity. Death is usually expected in the first decade of life. Unfortunately, most patients lack an HLA-matched sibling donor and alternative donors have been identified for transplant. This study reports on a five-year median follow-up (range: 985-2,355 days) in 11 Hurler Syndrome patients who underwent allogeneic BMT from partially mismatched related donors (PMRDs). The median age was 20 months (range: 11-44 months). The overall survival rate was 64% (95% CI 34-94%). The overall graft failure rate (36%) was higher than reported with matched sibling BMT. All patients with sustained engraftment experienced improvement in physical manifestations, such as corneal opacity, gum and tongue hypertrophy, hepatosplenomegaly and joint mobility. Skeletal abnormalities, such as dysostosis-multiplex, were stabilized but not reversed. Some patients have continued to show decline in neuropsychometric testing, while others appear to stabilize and one has demonstrated improvement. Until better methods for replacing enzyme activity are developed, BMT from a matched sibling of alternative donors can be considered a viable intervention for Hurler Syndrome patients to achieve partial improvement or stabilization from the deterioration caused by substrate storage, particularly in minimally affected patients early in life.

Actuarial Analysis↗

[Extensive Mongolian spot related to Hurler disease].

BACKGROUND: We report a case of a large blue mongolian spot which led to early diagnosis of Hurler's syndrome. This association is uncommon and should be recognized by dermatologists for early diagnosis and management. CASE REPORT: A male infant from Guinea, born to first-cousin parents, was seen at the age of 4.5 months for multiple, particularly extensive blue mongolian spots. Growth was +2 SD for age and the infant's psychomotor development was normal. A slight thickening of the skin was noticed without real dysmorphism. The blue spots extended over the entire posterior aspect and part of the anterior aspect of the trunk and involved all four limbs and the eyelids. The elbow and knee joints were moderately stiff and liver enlargement was palpated. The skin biopsy showed fusiform cells with melanin pigment tattooing the cytoplasm. No vacuolized epidermal cells were observed. Blood cell counts and liver and kidney tests were normal. Tests were positive for vacuolized lymphocytes and Gasser lymphocytes. Urine was positive for mucopolysaccharides and the enzymology study showed an alpha-L-iduronidase deficiency in serum and leukocytes, confirming the diagnosis of Hurler's disease. As no HLA compatible donor was available, no bone marrow graft was attempted. The child is a candidate for organoid gene therapy. DISCUSSION: Mongolian spots predominate in Asian, American Indian and black population (90% of the cases) compared with Caucasians (10%). The pathogenesis and pathogenic associations are unknown. The incidence of large widespread mongolian spots is also unknown and no precise criteria are available to define this entity. A few cases of extended mongolian spots associated with type 1 gangliosidosis and about 20 cases associated with Hurler's disease have been reported in the literature. The association with Hurler's disease is probably not fortuitous and several hypotheses have been put forward. Bone marrow transplantation can improve prognosis if performed early before onset of irreversible visceral disorders, emphasizing the importance of early diagnosis in children.

Consanguinity↗

Mild phenotype due to inverse duplication 4p16.3 - P15.3 including the Wolf-Hirschhorn critical region.

Duplication of distal 4p results in a recognizable clinical phenotype. We report here on a 3 year old girl with a de novo inverse duplication of the chromosome segment 4p16.3-p15.3. The symptoms in this patient are milder than those of previously described patients with 4p duplication syndrome and include a deep hairline, deep-set eyes, short pug nose, full cheeks, simian crease, clinodactily of the fifth digit, no speech development and a moderate psychomotor retardation. Fluorescence in situ hybridization (FISH) using a chromosome 4 painting probe confirmed that the extra material is of chromosome 4 origin. Further analysis with the Wolf-Hirschhorn critical region probe demonstrated the duplication of this region. The lysosomal hydrolase alpha-L-iduronidase (IDUA) gene which is mutated in mucopolysaccaridosis type I (MPS I) and mapped to 4p16.3 might be responsible for some of the MPS like facial features. A phenotype-genotype correlation analysis in combination with literature review was undertaken to allow a further delineation of partial trisomy 4p syndromes.

Abnormalities, Multiple↗

[Hurler's syndrome--early clinical suspicion].

BACKGROUND: Hurler's syndrome is a rare congenital metabolic disorder and is inevitably lethal when untreated. The presenting symptoms are usually vague, resembling those found in otherwise healthy children. MATERIAL AND METHODS: We present a patient with Hurler's syndrome and discuss the unspecific clinical signs and symptoms seen in these patients based on a review of relevant literature. RESULTS: A two-months-old infant boy was operated for a rightsided inguinal hernia. The anaesthesiologist had difficulty intubating the patient. During the following months the patient had a severe allergic reaction to vaccination, chronic rhinitis with recurrent upper airway infections, and diarrhoea and vomiting. Eventually, failure to gain weight, and psychomotoric delay led to a thorough clinical investigation. Extensive X-ray diagnostics and analysis of urine and serum concluded with Hurler's syndrome. INTERPRETATION: Clinical vigilance is needed in the diagnosis of Hurler's syndrome. Early symptoms, such as rhinitis and hernia, are vague and unspecific. Radiological features, such as broad costae or gibbus, are helpful in obtaining the diagnosis. Decreased level of alpha-L-iduronidase in serum confirms the diagnosis of Hurler's syndrome. Patients tend to be treated symptomatically before the eventual diagnosis of this syndrome.

Diagnosis, Differential↗

The mucopolysaccharidoses and mucolipidoses.

The mucopolysaccharidoses and mucolipidoses are recessively inherited lysosomal storage diseases. Each of the disorders can now be specifically identified in cultured fibroblasts. As a group these disorders clinically present with a Hurler-like phenotype. Genetic heterogeneity and variable expression of the same enzyme deficiency require a combined clinical and laboratory approach to the diagnosis of these disorders. This feature is demonstrated by mucopolysaccharidosis I. This diagnosis refers to a specific deficiency of the lysosomal enzyme alpha-L-iduronidase. Further characterization requires clinical assessment to determine whether the final diagnosis is the Hurler syndrome, the Scheie syndrome or the Hurler-Scheie compound. Clinically each of these three disorders may be difficult to distinguish from other mucopolysaccharidoses or mucolipidoses. There is no specific treatment currently available for any of these disorders. However, a specific diagnosis should be established in each case to insure an accurate prognosis (some of these disorders are compatible with near normal life expectancy and normal intelligence), appropriate genetic counseling for the family and timely use of prenatal diagnosis by amniocentesis which is available for each of these disorders.

Aspartylglucosaminuria↗