Skip to main content

Diseases Studied

The Rare Diseases Clinical Research Network is an NIH-funded research network of 20 active consortia or research groups working to advance treatment for diseases that are rare. Use the search tools on this page to find the diseases we currently study. You can reach out to the indicated consortia or research groups for more information on those diseases and studies underway.

This network focuses on clinical research and does not generally support clinical care outside of research activities. To learn about other rare diseases, please visit the Genetic and Rare Diseases Information Center (GARD), which is an NIH program that helps the public find reliable information about rare and genetic diseases. Their staff are specialists. Contact them at 1-888-205-2311 or email

All Diseases > Sly Syndrome

Sly Syndrome (MPS VII)

Alternative Names: Beta-Glucuronidase Deficiency (GUSB Deficiency); Mucopolysaccharidosis VII; Mucopolysaccharidosis 7; MPS Disorder-Type7 (MPS 7)

Disease Category: Lysosomal Diseases

A rare, inherited, lysosomal disorder, caused by a missing or abnormal enzyme that cannot break down glycosaminoglycans (GAGs, complex sugar molecules with amino groups that are critical components of connective tissues). Possible symptoms include hydrops fetalis (fluid accumulation throughout the body prior to birth), hydrocephalus (fluid accumulation in the brain), skeletal and heart valve abnormalities, facial dysmorphism (abnormal difference in structure), hepatosplenomegaly (liver and spleen enlargement), a narrow airway, vision and hearing loss, recurrent infections, apnea (cessation of breathing especially during sleep), carpal tunnel syndrome, and hernias (intestinal protrusions in the abdomen).

Research groups studying this disease

Lysosomal Diseases
LDN logo

Lysosomal Disease Network (LDN)