Bone marrow transplantation is the therapy of choice in patients affected by MPS I (Hurler syndrome), but a high incidence of rejection limits the success of this treatment.
In order to support the clinical application of hematopoietic stem cell (HSC) gene therapy for mucopolysaccharidosis I (MPS I), biosafety studies were conducted to assess the toxicity and tumorigenic potential, as well as the biodistribution of HSCs and progenitor cells (HSPCs) transduced with lentiviral vectors (LV) encoding the cDNA of the alpha-iduronidase (IDUA) gene, which is mutated in MPS I patients.
A correlation was observed between the MPS I patient clinical phenotype and the associated mutant alpha-L-iduronidase protein/enzyme activity expressed in CHO-K1 cells.
Mucopolysaccharidosis type I (Hurler syndrome) is caused by a deficiency of the enzyme alpha-L-iduronidase (IDUA), and is characterized by widespread lysosomal glycosaminoglycan (GAG) accumulation.
Long-Term Cognitive and Functional Outcomes in Children with Mucopolysaccharidosis (MPS)-IH (Hurler Syndrome) Treated with Hematopoietic Cell Transplantation.
Glycemic control and chronic dosing of rhesus monkeys with a fusion protein of iduronidase and a monoclonal antibody against the human insulin receptor.
In this work, fibroblasts from MPS I patients (p.W402X/p.W402X; p.R89W/p.W402X and p.Q70X/c.1739-1g > t) were treated with chloramphenicol, which resulted in 100-fold increase on IDUA activity on compound heterozygous fibroblasts. cDNA sequencing showed that only the alleles without the nonsense mutation were being amplified, even after treatment, leading us to suggest that the nonsense alleles were targeted to nonsense-mediated mRNA decay and that chloramphenicol acts through a mechanism other than SCRT.
So far, more than 100 IDUA causative mutations have been identified leading to three MPS I phenotypic subtypes: Hurler syndrome (severe form), Hurler/Scheie syndrome (intermediate form), and Scheie syndrome (mild form).
Report of 5 novel mutations of the α-L-iduronidase gene and comparison of Korean mutations in relation with those of Japan or China in patients with mucopolysaccharidosis I.