mucopolysaccharidosis type I (MPS I)

Mucopolysaccharidosis type I (MPS I) is a rare genetic condition, resulting from disease-causing changes in the IDUA gene called pathogenic variants. There are two different types of variants: • Null variants – cells cannot make the alpha-L-iduronidase enzyme • Missense variants – cells make a partly functional or severely reduced amount of the fully functional enzymeThe alpha-L-iduronidase enzyme breaks down large sugar molecules called glycosaminoglycans (GAGs). In people with MPS I, the enzyme is unable to break down GAGs and they build up in cells.Based on the severity of the condition, doctors categorise MPS I into two types, called phenotypes:• Attenuated MPS I • Severe MPS ITreatment options differ depending on MPS I phenotype. There are currently no tests that accurately determine MPS I phenotype. Using information from the MPS I Registry, researchers wanted to find out whether knowing the specific combination of the 2 disease-causing gene variants (genotype) can help predict whether a person has an attenuated or severe phenotype

17th Jan 2024

Looking at whether genetic testing can help doctors diagnose the severity of MPS I- a plain language summary

25th Nov 2022

Plain language summary of a study looking at the age at diagnosis and time to start of treatment in individuals with mucopolysaccharidosis type I (MPS I)