Mucopolysaccharidosis type I (MPS I) is a rare autosomal recessive disorder, caused by deficiency of the enzyme α-L-iduronidase (IDUA), which is required for the lysosomal degradation of the glycosaminoglycans (GAGs) dermatan and heparan sulfate.1 Here, IDUA is linked to mucopolysaccharidosis type 1.