ylumbelliferyl-ƒ¿-L-iduronide as a substrate, ƒ¿-L-iduronidase activity was meas ured in leukocytes and in lymphoblastoid cells obtained from patients with ƒ¿-L-iduronidase deficiency and from obligate heterozygotes for this disease . There was complete discrimination between ƒ¿-L-iduronidase activities measured using 4-methylumbelliferyl-ƒ¿-L-iduronide in leukocytes and in lymphoblastoid cells...

Mucopolysaccharidosis type I (MPS I) is a lysosomal storage disorder caused by deficiency of the hydrolase α-L-iduronidase. MPS characterized broad range disease manifestations. This includes devastating neurocognitive and bone manifestations short life expectancy in severely affected patients. Neurocognitive are typically limited more attenuated I, but patients may still suffer from severe som...

Skin fibroblasts cultured from patients affected with the Hurler or Scheie syndromes (mucopoly-saccharidoses I or V, respectively) have a functional deficiency of a protein required for catabolism of sulfated mucopolysaccharide that has been designated the "Hurler corrective factor." We now show Hurler factor purified from normal human urine to be associated with alpha-L-iduronidase activity. C...

BACKGROUND Treatments now available for mucopolysaccharidosis I require early detection for optimum therapy. Therefore, we have developed an assay appropriate for newborn screening of the activity of the relevant enzyme, alpha-L-iduronidase. METHODS We synthesized a new alpha-L-iduronidase substrate that can be used to assay the enzyme by use of tandem mass spectrometry together with an inter...

A 1-year-old child is referred to your office for a developmental assessment due to delayed speech and gross motor skills. You notice coarse facial features and on physical examination document corneal clouding, hepatosplenomegaly, and numerous skeletal deformities. You suspect a metabolic disorder and request an urgent referral to a metabolic specialist. The specialist clinically diagnoses Hur...

BACKGROUND Mucopolysaccharidosis type I is caused by deficiency of α-L-iduronidase. Currently available treatment options include an allogeneic hematopoietic stem cell transplant and enzyme replacement therapy. Exogenous enzyme therapy appears promising but the benefits may be attenuated, at least in some patients, by the development of an immune response to the delivered enzyme. The incidence ...

This is a review article regarding the new types of Mucopolysacharidose disease and re­lated diagnostic tests. Recently has been found that Hurler's and Scheie's diseases are due to the deficiency of Alpha-Iduronidase and San­filippo's disease is due to Heparan-N-Sulphatase and N-Acetyl-Alpha-D-Glucosaminidase defici­ency. 

BACKGROUND Mucopolysaccharidosis type I (MPS I) is a debilitating hereditary disease characterized by alpha-L-iduronidase (IDUA) deficiency and consequent inability to degrade glycosaminoglycans. The pathological accumulation of glycosaminoglycans systemically results in severe mental retardation and multiple organ dysfunction. Enzyme replacement therapy with recombinant human alpha-L-iduronida...

Enzyme replacement therapy (ERT) for the lysosomal storage disease mucopolysaccharidosis I (MPS I) involves i.v. injection of alpha-l-iduronidase, which can be taken up by cells throughout the body. While a significant immune response to ERT has been shown in patients with MPS I, little is known about what effect anti-enzyme antibodies have on treatment efficacy. In this issue of the JCI, Dicks...

BACKGROUND Cardiovascular disease, a progressive manifestation of α-L-iduronidase deficiency or mucopolysaccharidosis type I, continues in patients both untreated and treated with hematopoietic stem cell transplantation or intravenous enzyme replacement. Few studies have examined the effects of α-L-iduronidase deficiency and subsequent glycosaminoglycan storage upon arterial gene expression to ...