Sly Syndrome (MPS VII)
What is Sly syndrome?
Sly syndrome, also known as mucopolysaccharidosis type VII (MPS VII), is caused by the body not having enough of a specific enzyme called β-glucuronidase. Without normal levels of this enzyme, extra amounts of carbohydrates, called mucopolysaccharides, build up in the cells of the body. Many parts of the body can be affected by Sly syndrome, including the bones (skeleton), eyes, brain, muscles, spleen, and heart. Symptoms of Sly syndrome range from severe (noticeable at birth) to mild (appearing during late childhood).
How common is Sly syndrome?
About 1 in 250,000 babies are born with Sly syndrome each year in the United States
What can be done for Sly syndrome?
Identifying this condition early (soon after birth) may lead to reduced symptoms and an improved quality of life. Certain symptoms of this condition can be treated with physical and occupational therapies. There is also a form of treatment that replaces the missing β-glucuronidase enzyme - this is called enzyme replacement therapy (ERT). While ERT isn’t a complete cure for Sly syndrome, it can make many of the symptoms less severe, helping people with Sly syndrome live longer, fuller lives. Some symptoms of the condition can also be treated with a bone marrow transplant.
How is Sly syndrome inherited?
Sly syndrome is caused by changes in the GUSB gene. It is a recessive inherited condition, which means that a person must inherit two altered copies of the GUSB gene, one from each parent, in order to have the disease. People who have only one copy of the altered GUSB gene are called carriers, and are not expected to have symptoms of the condition. If a baby is identified as a carrier for Sly syndrome with Eli screening, genetic counseling and additional testing in the parents is recommended.