Recombinant human beta-glucuronidase (rhGUS) is an investigational enzyme replacement therapy in development for Mucopolysaccharidosis 7 (MPS 7), also known as Sly Syndrome. 

MPS 7 is a genetic metabolic disorder caused by a deficiency of the lysosomal enzyme beta-glucuronidase, which is required for the breakdown of certain complex carbohydrates known as glycosaminoglycans (GAGs). The inability to break down GAGs leads to their accumulation in many tissues, resulting in serious disease.

Patients with MPS 7 may have abnormal coarsened facial features, enlargement of the liver and spleen, airway obstruction, lung disease, cardiovascular complications, joint stiffness, short stature, and skeletal disease. The severe cellular and organ dysfunction of MPS 7 typically leads to death in the teens or early adulthood.

There are no approved therapies for MPS 7.

Ultragenyx has licensed rights to rhGUS from Saint Louis University.

Mechanism of Action

rhGUS is an investigational therapy intended to replace the deficient lysosomal enzyme beta-glucuronidase to help break down the glycosaminoglycans that accumulate in the tissues of patients with MPS 7.

News & Other Information

Press Releases

Data Presentations/Publications

Clinical Trials



Phase 3


Mucopolysaccharidosis 7
(MPS 7)


200 in the developed world

Disease mechanism

Lysosomal enzyme deficiency

Key Symptoms

Large liver/spleen
Pulmonary disease
Heart valve abnormalities
Skeletal abnormalities

treatment mechanism

Enzyme replacement