Mutations in the GUSBgene are associated with Mucopolysaccharidosis type VII (MPS VII), also known as Sly Syndrome, an ultra-rare, pan-ethnic, progressive disease that affects lysosomal storage/function. In MPS VII, there is a build-up of glycosaminoglycans (GAGs) due to deficient activity of the lysosomal enzyme β-glucuronidase, which catalyses hydrolysis of β-D-glucuronic acid residues from the non-reducing end of glycosaminoglycans.
The disease is inherited in an autosomal recessive manner and the estimated prevalence is < 1:1,000,000, accounting for less than 1,000 individuals globally. Patients with MPS VII can present in the neonatal period with non-immune hydrops fetalis, cholestatic jaundice, hepatosplenomegaly, and stillbirth, or in early childhood with developmental delay, intellectual disability, skeletal abnormalities, craniofacial features, among other symptoms.
GUSB