Disease Directory Mucopolysaccharidosis Type VII
Metabolic

Mucopolysaccharidosis Type VII

Also known as: MPS VII, Sly syndrome, GUSB deficiency, beta-glucuronidase deficiency

Prevalence

1-9 per 1,000,000 (Orphanet)

Onset

Neonatal, Infantile, Childhood

Type

Autosomal recessive genetic

Gene

GUSB

About Mucopolysaccharidosis Type VII

Mucopolysaccharidosis type VII (MPS VII, Sly syndrome) is an extremely rare lysosomal storage disorder caused by deficiency of beta-glucuronidase (GUSB), resulting in accumulation of dermatan sulfate, heparan sulfate, and chondroitin sulfate. Clinical features range from severe hydrops fetalis and neonatal death to mild forms surviving into adulthood. Vestronidase alfa (Mepsevii) is approved as enzyme replacement therapy for non-CNS manifestations.

Common Clinical Features

Hydrops fetalis Coarse facial features Hepatosplenomegaly Skeletal dysplasia Intellectual disability Recurrent respiratory infections Corneal clouding

Clinical Trial Eligibility Tips

What to know before applying to Mucopolysaccharidosis Type VII trials.

Vestronidase alfa (Mepsevii) is approved — trials focus on CNS outcomes, intrathecal delivery, or next-generation approaches

Beta-glucuronidase enzyme activity in leukocytes is the primary diagnostic biomarker required for enrollment

Urinary glycosaminoglycan (GAG) quantification is a key pharmacodynamic endpoint in ERT trials

MPS VII is extremely rare — contact MPS Society for disease-specific trial matching and registry enrollment

Patient Resources

Patient Organization

National MPS Society

Visit website ↗

Natural History Registry

MPS Society Patient Registry

Join registry ↗

Orphanet

European reference resource for rare diseases (ORPHA:584)

View on Orphanet ↗

NORD

National Organization for Rare Disorders

Search NORD ↗

Find recruiting Mucopolysaccharidosis Type VII trials

Search 500,000+ studies from ClinicalTrials.gov, filtered for Mucopolysaccharidosis Type VII. Updated daily.

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