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PubMed2002

[Ocular Manifestation of Mucopolysaccharidosis I-S (Scheie's Syndrome)].

BACKGROUND: Bilateral stromal corneal opacifications are a differential diagnostical challenge to identify associated systemic diseases. CASE-REPORT: A 47-year old civil engineer (height 167 cm) with bilateral stromal corneal clouding presented with visual loss for the last 27 years: VA 20/100 OD and 20/50 OS (following penetrating keratoplasty OS). The cornea showed milky-whitish, cloudy, diffuse stromal deposits without a separate lipoid arc. The posterior segment showed tapetoretinal degeneration. Scotopic ERG was decreased. A suspicious stiffness of interphalangeal joints on both hands was observed. There was an aortic and mitral insufficiency grade I. Serum levels of LDL, HDL and triglycerides were normal. The biomicroscopical diagnosis of Scheie's syndrome (mucopolysaccharidosis I-S) was confirmed by a deficiency of alpha-L-iduronidase in leukocytes (0.02 nmol/min/mg protein, normal range: 0.3 - 1.5). CONCLUSION: The differential diagnosis of bilateral corneal stromal opacification includes in addition to the mucopolysaccharidoses HDL-deficiency diseases (LCAT deficiency, Tangier disease, Fish eye disease), Schnyder's crystalline stromal dystrophy, cystinosis, gout and mucolipidoses. MPS I-S may easily be detected by alpha-L-iduronidase deficiency in leukocytes and increased mucopolysaccharides in the urine. Furthermore, patients with MPS I-S need general medical care because of cardiovascular abnormalities, joint stiffness and myopathies.

Corneal Opacity↗
PubMed2004

Cord-blood transplants from unrelated donors in patients with Hurler's syndrome.

BACKGROUND: Hurler's syndrome (the most severe form of mucopolysaccharidosis type I) causes progressive deterioration of the central nervous system and death in childhood. Allogeneic bone marrow transplantation before the age of two years halts disease progression and prolongs life, but many children lack a bone marrow donor. We investigated the feasibility of using cord-blood transplants from unrelated donors and a myeloablative preparative regimen that did not involve total-body irradiation in young children with Hurler's syndrome. METHODS: Between December 1995 and October 2002, 20 consecutive children with Hurler's syndrome received busulfan, cyclophosphamide, and antithymocyte globulin before receiving cord-blood transplants from unrelated donors. The children were subsequently evaluated for engraftment, adverse effects, and effects on disease symptoms. RESULTS: Cord-blood donors had normal alpha-L-iduronidase activity (mean number of cells, 10.53x10(7) per kilogram of body weight) and were discordant for up to three of six HLA markers. Neutrophil engraftment occurred a median of 24 days after transplantation. Five patients had grade II or grade III acute graft-versus-host disease; none had extensive chronic graft-versus-host disease. Seventeen of the 20 children were alive a median of 905 days after transplantation, with complete donor chimerism and normal peripheral-blood alpha-L-iduronidase activity (event-free survival rate, 85 percent). Transplantation improved neurocognitive performance and decreased somatic features of Hurler's syndrome. CONCLUSIONS: Cord blood from unrelated donors appears to be an excellent source of stem cells for transplantation in patients with Hurler's syndrome. Sustained engraftment can be achieved without total-body irradiation. Cord-blood transplantation favorably altered the natural history of Hurler's syndrome and thus may be important to consider in young children with this form of the disease.

Blood Donors↗
PubMed1984

Antenatal diagnosis of mucopolysaccharidosis type I (Hurler's disease) is not possible by electron microscopy of uncultured amniotic fluid cells.

Mucopolysaccharidosis type I (MPS I) is a lysosomal storage disorder characterised by the deficient activity of iduronidase and by the presence of MPS vacuoles in many tissues of affected patients. We studied whether these characteristics could be used for the antenatal diagnosis of the disease. We obtained amniotic fluid cells from two pregnancies at risk for MPS I, one pregnancy at risk for GSD II (another lysosomal disease), and eight normal control pregnancies. Measurements of iduronidase activity in cultured amniotic fluid cells indicated the presence of a MPS I fetus in one high risk pregnancy and an unaffected fetus in the other. This diagnosis was confirmed at delivery. On electron microscopy the uncultured amniotic fluid cells exhibited MPS-like vacuoles in the pregnancy with a GSD II fetus, in three of eight normal pregnancies, and in the pregnancy at risk for MPS I that had a normal fetus. No such vacuoles were seen in the pregnancy with the MPS I fetus. These false positive and false negative findings indicate that antenatal diagnosis of MPS I cannot be based on the electron microscopic presence or absence of MPS I vacuoles in uncultured amniotic fluid cells.

Amniotic Fluid↗
PubMed1997

Mucopolysaccharidosis type I: identification of novel mutations that cause Hurler/Scheie syndrome in Chinese families.

The complementary and genomic DNA segments of the alpha-L-iduronidase gene from two Chinese mucopolysaccharidosis type I Hurler/Scheie (MPS IH/S) patients were amplified by polymerase chain reaction (PCR) and DNA sequencing was done to study their molecular lesions. Patient W3 has heterozygous mutations; the maternal allele has M1I (G to A transition in the initiation codon ATG) and the paternal allele has Y343X (C to G transversion in exon 8 leading to in frame deletion of codons 325-343 from the mRNA owing to false splicing). Patient W2 is homozygous for mutation T364M (C to T transition in codon 364). The mutation was paternally inherited. A de novo deletion or gene conversion event may have resulted in apparent homozygosity for T364M. Expression of Y343X and T364M showed trace amounts of alpha-L-iduronidase activity compared to that of normal cDNA upon transfection into COS-7 cells.

Animals↗
PubMed1987

Bone marrow transplantation in canine mucopolysaccharidosis I. Effects within the central nervous system.

Five dogs with mucopolysaccharidosis I, a model of human Hurler/Scheie syndrome, were transplanted with marrow from phenotypically normal littermates at 5 mo of age. At 3 and 9 mo posttransplantation, biopsies of cerebral cortex, liver, and cerebrospinal fluid were obtained. The alpha-L-iduronidase levels in these tissues were 0.8-7.4, 26-45, and 6.3-14.9% of the paired donor tissues, respectively. Although iduronidase was present in relatively low levels in the recipients' brains and cerebrospinal fluid at both biopsy times, reduction in brain glycosaminoglycan (GAG) was comparable to that observed in liver. Ultrastructural studies of cells within the transplanted dogs' brains showed less lysosomal distension and storage product than in affected, nontransplanted, littermate controls. The most marked clearing of stored GAG was in cells surrounding blood vessels, but decreased lysosomal storage in neurons and glial cells was also observed. Urinary GAG excretion also decreased to near normal levels by 5 mo posttransplantation.

Animals↗
PubMed2005

The first 5 years of clinical experience with laronidase enzyme replacement therapy for mucopolysaccharidosis I.

Mucopolysaccharidosis I (MPS I, McKusick 25280) is caused by the deficiency or absence of the lysosomal enzyme, alpha-L-iduronidase (EC 3.2.1.76). This inherited disease causes progressive cellular, tissue and organ damage across the entire phenotypic spectrum. Disabling, multi-organ disease is the rule, and generally results in death between the first and fourth decades of life. Recently, laronidase (Aldurazyme) [Genzyme], a specific recombinant human alpha-L-iduronidase) became commercially available as long-term enzyme replacement therapy. Results from the Phase I/II and III extended clinical studies have shown that laronidase safely and effectively alleviates many systemic signs and symptoms of this progressive multisystemic disease. Clinically meaningful and sustained improvements in pulmonary function and functional capacity have been observed in Phase III study patients. Significant and sustained reductions in urinary glysosaminoglycan (GAG) excretion and hepatomegaly have also been observed. Improvements in sleep apnoea and joint range of motion occurred in patients with the most severe symptoms at baseline. Improvements in Disability Index scores as measured using the CHAQ and HAQ questionnaires were modest, which may have been related to the fact that these disability measuring tools are not disease-specific. Anecdotal reports of improvements in the performance of daily activities further add to the therapeutic benefits, as do case histories pointing at stabilisation or improvement of symptomatology in various organs, such as the eyes, heart, and muscles. With the availability of specific treatment, the importance of early recognition of the disease and appropriate therapeutic intervention has increased. The variability in clinical symptomatology is reviewed in detail and may allow for a better understanding of the diagnostic and therapeutic challenges. Results of the clinical trials and their initial extension periods, as well as the anecdotal experiences of physicians with laronidase in non-study settings, are discussed.

Clinical Trials as Topic↗
PubMed2002

Laronidase.

BioMarin Pharmaceutical is developing laronidase, recombinant alpha-L-iduronidase enzyme replacement therapy for the treatment of mucopolysaccharidosis I (MPS-I) [the most severe form of this is called Hurler syndrome]. The company has received US and European orphan drug designation for the enzyme and has fast-track review status with the FDA. In 1998, BioMarin Pharmaceutical and Genzyme General formed a joint venture for development and marketing of laronidase. A Phase I trial in 10 patients with a range of disease severity of MPS-I required for US and European filing was completed at the Harbor-UCLA Medical Center in California. This open label trial involved weekly infusions with laronidase. The two-year follow-up data revealed sustained and, in certain parameters, improved clinical results recorded at the end of 1 year of therapy. BioMarin and Genzyme General have completed a pivotal, Phase III trial in the centres in the USA, Canada and Europe, including patients with Hurler-Scheie and Scheie syndromes. In a multicentre, double-blind, placebo-controlled study, all 45 patients with MPS-I have received at least their initial weekly infusion of laronidase. Patients are being evaluated over a 6-month period. BioMarin Pharmaceutical and Genzyme General have filed on 15 April 2002 the first portion of a 'rolling' BLA with the US FDA for use of laronidase in the treatment of MPS-I. The companies are planning to complete the BLA filing in Q3 2002. The application will include 6-month data from the ongoing open-label Phase III extension study and also the 6-month data from the placebo-controlled part of the Phase III study. In the open-label extension study, patients from both the treatment and placebo arms of the Phase III trial received weekly infusions of laronidase for at least 6 months. The response from the US FDA is anticipated during the H1 of 2003. Both companies plan to initiate two new clinical trials in patients with MPS-I. One study will enrol patients with MPS-I under 5 years old. Another study will investigate laronidase in patients with advanced clinical symptoms of MPS-I. Additionally, patients from the ongoing Phase III study will continue to receive treatment with laronidase. On 1 March 2002, BioMarin and Genzyme filed a marketing approval application with European regulatory authorities for AldurazymeOE for the treatment of MPS-I. Mucopolysaccharidosis I is a rare autosomal recessive lysosomal storage disorder caused by alpha-L-iduronidase deficiency. Its manifestations in children can include growth and developmental delay, enlargement of spleen and liver, skeletal deformity, cardiac and pulmonary impairment, vision or hearing loss and mental dysfunction. At present, bone marrow transplantation is the only available treatment.

Animals↗
PubMed1979

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.

Adult↗
PubMed1996

[Gene therapy in lysosomal diseases].

The study of the mechanisms of secretion and recapture of lysosomal enzymes has lead to the proposal of a treatment of lysosomal diseases by enzyme replacement. Autologous implants of genetically modified cells which secrete enzymes ensure systemic distribution of the lacking enzyme. A procedure which permits reimplantation of genetically modified fibroblasts is described. The stable secretion of human glucuronidase by autologous fibroblasts was thus obtained in animal species. This approach should by applicable to the treatment of Hurler's syndrome by obtaining the production and distribution of alpha-L-iduronidase in patients lacking this enzyme by retroviral transfer of the human alpha-L-iduronidase gene to cultured fibroblasts and by preparation of implants.

Animals↗
PubMed1989

Mucopolysaccharidosis I presenting with endocardial fibroelastosis of infancy.

We describe two female infants with Hurler syndrome (mucopolysaccharidosis I) whose deaths are attributed to cardiac failure with associated, autopsy-confirmed endocardial fibroelastosis. One infant had confirmed alpha-L-iduronidase deficiency in cultured dermal fibroblasts, and the other infant had histologic evidence of tissue mucopolysaccharide accumulation at autopsy and a sibling with confirmed alpha-L-iduronidase deficiency and the Hurler syndrome phenotype. Clear cells ("Hurler" cells) were identified within the myocardium and endocardium of both infants. We propose that the ventricular mural accumulation of mucopolysaccharides induced extensive proliferation of elastic or collagen fibers within the endocardium. Cardiac failure may precede recognition of clinical and roentgenographic features of Hurler syndrome. Our findings and a literature review suggest that certain heritable storage disorders, including mucopolysaccharidosis I, should be considered when infants have clinical electrocardiographic and echocardiographic findings consistent with endocardial fibroelastosis or have autopsy-documented endocardial fibroelastosis.

Endocardial Fibroelastosis↗
PubMed1990

Variation of lysosomal enzyme activity with gestational age in chorionic villi.

The activities of 14 lysosomal enzymes in chorionic villi at gestational ages of 6-12 weeks were assayed. Arylsulphatases A and B, alpha-glucosidase and beta-glucuronidase activities increased with advancing gestational age. When compared with the activity in cultured amniotic fluid cells, arylsulphatase A, beta-galactosidase, alpha-glucosidase, heparan N-sulphatase, alpha-L-iduronidase, alpha-mannosidase, neuraminidase, and sphingomyelinase showed significant differences. All except beta-glucuronidase showed lower activity in chorionic villi than in cultured amniotic fluid cells. Prenatal diagnosis using chorionic villi was possible except for alpha-L-iduronidase. Storage at -20 degrees C up to 42 days did not significantly affect activity. The results emphasize the importance of using fresh or frozen age-matched control tissue for diagnosis.

Amniotic Fluid↗
PubMed1979

Two species of lysosomal organelles in cultured human fibroblasts.

Cultured diploid human skin fibroblasts were fractionated by a procedure that maximizes recovery of particles containing acid hydrolases. The cells were detached by controlled trypsinization, disrupted by N2 cavitation at low pressure and fractionated at 18,000 x g on a self-generating gradient of colloidal silica. This procedure separated two species of particles that could be consisered lysosomal. The denser one (peak density 1.11) was apparently free of other contaminants, but the more buoyant one (peak density 1.085) sedimented with or close to the peaks of other organelles, including mitochondria, Golgi, endoplasmic reticulum and plasma membranes. The two populations of particles contained acid hydrolases (phosphatase, six glycosidases and four cathepsins) in roughly equal proportions, displayed latency, had similar turnover of 35S-mucopolysaccharide in normal as well as in iduronidase-deficient cells, and were recipients of alpha-L-iduronidase, previously shown to be acquired by receptor-mediated endocytosis. Acid phosphatase staining of the intact fibroblasts showed residual bodies scattered throughout the cytoplasm and, near the nucleus, a prominent network of tubules and associated dilatations and knob-like enlargements. In both thin and thick sections, these appeared continuous, as if forming a three-dimensional network similar to the network described by Novikoff (1976) as GERL. Ultrastructural studies of the isolated fractions showed the denser lysosomal peak to be composed of small round or oblong acid phosphatase-positive bodies. The more buoyant peak contained the nonlysosomal organelles predicted from the biochemical markers, small acid phosphatase-positive bodies and large multivesiculated structures in which acid phosphatase was localized in a matrix surrounding apparently empty vesicles. These large structures may represent fragments of GERL. We suggest that the dense and buoyant lysosomal organelles originate primarily from residual bodies and the GERL network, respectively.

Cathepsins↗
PubMed1986

Heparin trisaccharides with nonreducing 2-amino-2-deoxy-alpha-D-glucopyranosyl end-groups suitable as substrates for catabolic enzymes.

Heparin trisaccharides having the sequence O-(2-amino-2-deoxy-alpha-D-glucopyranosyl)-(1----4)-O-alpha-L- idopyranosyluronic acid-(1----4)-2,5-anhydro-D-[1-3H]mannitol have been prepared, as substrate models for studying sulfatases of heparan sulfate catabolism, by alpha-L-iduronidase cleavage of previously reported heparin tetrasaccharides, with additional chemical and enzymic modification as required. Three series are described, including isomeric sulfate esters of that trisaccharide with no N-substituent, with N-acetyl substitution, and with N-sulfate substitution. New features of the substrate specificity of the hydrolases used, including iduronate sulfatase, alpha-L-iduronidase, glucosamine 6-sulfate sulfatase, and heparin sulfamidase, were observed, and simple procedures for partial purification of these hydrolases are reported. The structures assigned to the trisaccharides are supported by the mode of preparation, reactions, regularities in electrophoretic behavior, and identities of the products of deamination.

Carbohydrate Sequence↗
PubMed2000

[Mucopolysaccharidosis type I in Morocco: clinical features and genetic profile].

BACKGROUND: Mucopolysaccharidoses (MPS) are inherited metabolic disorders due to lysosomal enzyme deficiencies, leading to glycosaminoglycan accumulation in lysosomes of different tissues. The aim of this study was to characterize MPS types, particularly MPS I, which are difficult to differentiate by clinical features. PATIENTS AND METHODS: Over a period of three years (June 1996-May 1999), 16 Moroccan patients (3-20 years old) with MPS were investigated. Twelve of them came from the Souss region. In subjects with suspected clinical MPS I or II, the diagnosis was confirmed by biochemical investigations, which included the quantification of total glycosaminoglycans (GAGs) released in urine, their identification, and the assay of alpha-L-iduronidase activity in leucocytes. A molecular analysis was performed in parallel, to provide the genetic proof of the diagnosis. RESULTS: These 16 patients belonged to 12 families, nine of which were consanguineous (75%). Twelve patients had Hurler syndrome and three had Hurler/Scheie's syndrome; no case of Scheie's syndrome was observed. Short stature, coarse face, organomegaly, hernia, cardiac disease, mental delay and dysostosis were observed in variable degrees. We report three cases without corneal clouding. Increased total urinary GAGs, identified as dermatan sulfate and heparan sulfate by thin-layer chromatography and total deficiency of alpha-L-iduronidase activity, were noted in studied subjects. At the molecular level the P533R mutation was detected in 24 among 26 alleles studied. CONCLUSION: It is now possible to perform the screening of MPS I and II in Morocco by analysis of clinical, radiologic observations and biological investigation. The predominance of P533R mutation could permit the screening of healthy heterozygotes and genetic counselling for families of Moroccan descent.

Adolescent↗
PubMed2004

Craniofacial abnormalities in a murine knock-out model of mucopolysaccharidosis I H: a computed tomography and anatomic study.

The genetic mucopolysaccharidoses are a group of lysosomal storage diseases in which mucopolysaccharides (glycosaminoglycans) accumulate as the result of a malfunction or lack of a lysosomal degradation enzyme. There are currently seven known forms of mucopolysaccharidoses. Type I results from an enzymatic deficiency of alpha-L-iduronidase. There are three subtypes of mucopolysaccharidoses I that are commonly recognized: Hurler syndrome, Hurler-Scheie syndrome, and Scheie syndrome. Of the three subtypes, Hurler syndrome has the most severe clinical picture. Craniofacial anomalies and cognitive impairment are some of the more pronounced features of Hurler syndrome. Hurler syndrome has been described in cats, dogs, mice, and human beings and is inherited as an autosomal recessive trait. The biochemical nature of the disease is preserved across species lines. Clinically, the disease has similar effects in human beings and animals. It has been difficult to reverse the phenotype of the disease even with replacement of the defective alpha-L-iduronidase enzyme. The purpose of this study is to characterize the cranio-facial differences in the murine knock-out model of Hurler syndrome objectively. Twenty-three measurements were taken from computed tomographic scans in a coronal and sagittal plane on 24 black C57/B6 knock-out Hurler syndrome mice. The seven statistically significant measurements are width of the cervical canal, height of the foramen magnum, width between the external auditory canals, width of the skull base at the mandibular condyles, midocular distance, spread of the mandibular condyles, and width of the zygoma at the maxilla. This information now provides researchers with objective data from living Hurler syndrome-affected mice that will allow them to follow therapies directed at improving craniofacial outcomes for any therapy over time.

Animals↗
PubMed1998

Murine MPS I: insights into the pathogenesis of Hurler syndrome.

Mucopolysaccharidosis type I (MPS I) is an autosomal recessive disease resulting from deficiency of the lysosomal enzyme alpha-L-iduronidase. A murine model which shows complete deficiency in alpha-L-iduronidase activity has been developed and shows phenotypic features similar to severe MPS I in humans. Here we report on the long-term clinical, biochemical, and pathological course of MPS I in mice with emphasis on the skeletal and central nervous system (CNS) manifestations. Affected mice show a progressive clinical course with the development of coarse features, altered growth characteristics and a shortened life span. Progressive lysosomal accumulation is seen in all tissues. Skeletal manifestations represent the earliest clinical finding in MPS I mice with histologic analysis of growth plate and cortical bone revealing evidence that significant early pathology is present. Analysis of the CNS has revealed the novel finding of progressive neuronal loss within the cerebellum. In addition, brain tissue from MPS I mice shows increased levels of GM2 and GM3 gangliosides. This murine model clearly shows phenotypic and pathologic features which mimic those seen in severe human MPS I and should be an invaluable tool for the study of the pathogenesis of generalized storage disorders.

Animals↗
PubMed1990

[Bone marrow transplantation in mucopolysaccharidosis type I, Hurler-Scheie variety. Metabolic correction and clinical results].

Bone marrow transplant has proved to be an effective treatment in some hereditary metabolic diseases and, especially, in mucopolysdaccharidosis (MPS). A 9-year-old girl, of consanguineous parents, with MPS Type I, Hurler-Scheie syndrome, received a BMT from her heterozygous, HLA-compatible mother. -L-iduronidase activity in leukocytes and fibroblasts was undetectable and glycosaminoglycans (GAG) excretion in urine was very high. BMT conditioning treatment consisted of Busulfan (16 mg/kg) and Cyclophosphamide (120 mg/kg); clinical course was uneventful. Sixty days post-BMT iduronidase activity in leukocytes was similar to that of the donor and GAG levels were normal at 12 months. Echocardiography showed regression in hypertrophic myocardiopathy. Previously enlarged and vacuole-filled skin fibroblasts became reduced in size and vacuole content. The most notable clinical effects were: improved facial features, increased height, disappearance of visceromegalies, gradual clearing of corneal opacities with improved vision and reduced joint stiffness. It is concluded that the gradual deterioration in patients with MPS-I may be arrested and many clinical features improved by BMT.

Bone Marrow Transplantation↗
PubMed1983

The antithrombin-binding sequence in heparin. Identification of an essential 6-O-sulfate group.

An octasaccharide with high affinity for antithrombin, isolated after partial deaminative cleavage of heparin, was previously found to have an L-iduronosyl-N-acetylglucosaminyl-6-O-sulfate nonreducing terminal disaccharide unit. After digestion of this octasaccharide with alpha-L-iduronidase and N-acetylglucosamine-6-sulfate sulfatase, two fractions, with high and low affinity for antithrombin, respectively, were isolated by affinity chromatography on antithrombin-Sepharose. Structural analysis showed that the high affinity fraction contained intact octasaccharide, whereas the low affinity fraction consisted of the expected heptasaccharide, lacking a 6-sulfate group on the terminal N-acetylglucosamine residue. Digestion of the octasaccharide with alpha-L-iduronidase only yielded heptasaccharide which was identical with the low affinity species except for the presence of this 6-sulfate group. This less degraded heptasaccharide retained high affinity for antithrombin. It is concluded that the 6-sulfate group on the N-acetylglucosamine residue is of critical importance to the interaction between heparin and antithrombin.

Animals↗