The mucopolysaccharidoses are a group of inherited metabolic diseases in which a defective or missing enzyme causes large amounts of complex sugar molecules to accumulate in harmful amounts in the body's cells and tissues. This accumulation causes permanent, progressive cellular damage that affects appearance, physical abilities, organ and system functioning, and, in most cases, mental development. Depending on the type of mucopolysaccharidosis, affected individuals may have normal intellect or may be profoundly impaired, may experience developmental delay, or have severe behavioral problems. Physical symptoms generally include coarse or rough facial features, thick lips, an enlarged mouth and tongue, short stature with a disproportionately short trunk (dwarfism), abnormal bone size or shape (and other skeletal irregularities), thickened skin, enlarged organs such as the liver or spleen, hernias, and excessive body hair growth.
Currently there is no cure for these disease syndromes. Medical care is directed at treating systemic conditions and improving the person's quality of life. Physical therapy and daily exercise may delay joint problems and improve the ability to move. Surgery to remove tonsils and adenoids may improve breathing among affected individuals with obstructive airway disorders and sleep apnea. Surgery can also correct hernias, help drain excessive cerebrospinal fluid from the brain, and free nerves and nerve roots compressed by skeletal and other abnormalities. Corneal transplants may improve vision among patients with significant corneal clouding. Enzyme replacement therapy has proven useful in reducing non-neurological symptoms and pain. In 2006, the FDA approved the drug idursulfase (Elaprase) for the treatment of MPS II (Hunter syndrome). This is the first drug shown to have any benefit for one of the mucopolysaccharidoses.
The mucopolysaccharidoses syndromes share many clinical features but have varying degrees of severity. Most individuals with a mucopolysaccharidosis syndrome generally experience a period of normal development followed by a decline in physical and mental function. Longevity is dependent upon the particular syndrome. For example, children with a form of mucopolysaccharidosis called Hurler syndrome often die before age 10 from obstructive airway disease, respiratory infections, or cardiac complications. A child with the type known as Scheie syndrome can live into adulthood, while one with a mild case of the type known as Hunter syndrome may live into his or her 50s or beyond.
The National Institute of Neurological Disorders and Stroke (NINDS) conducts research in its laboratories at the National Institutes of Health (NIH) and also supports additional research through grants to major medical institutions across the country. Currently, scientists are working to identify the genes associated with the mucopolysaccharidoses syndromes and plan to test new therapies in animal models and in humans. Research funded by the Institute has shown that viral-delivered gene therapy in animal models of the mucopolysaccharidoses can stop the buildup of storage materials in brain cells and improve learning and memory. Researchers are planning additional studies, but it may be years before such treatment is available to humans.
National MPS Society, Inc.
Dedicated to finding cures for mucopolysaccharidosis (MPS) and related diseases. Provides hope and support for affected individuals and their families by sponsoring research, advocacy, and awareness programs.
PO Box 14686
Durham, NC 27709-4686
National Organization for Rare Disorders (NORD)
Federation of voluntary health organizations dedicated to helping people with rare "orphan" diseases and assisting the organizations that serve them. Committed to the identification, treatment, and cure of rare disorders through programs of education, advocacy, research, and service.
55 Kenosia Avenue
Danbury, CT 06810
National Tay-Sachs and Allied Diseases Association
The mission of the National Tay-Sachs & Allied Diseases Association is to lead the fight to treat and cure Tay-Sachs, Canavan and related genetic diseases and to support affected families and individuals in leading fuller lives.
2001 Beacon Street
Boston, MA 02135
Hunter's Hope Foundation
[A Leukodystrophy Resource]
Fosters awareness about Krabbe disease and other leukodystrophies, works to promote early detection through newborn screening, provides information and service linkages to families, and funds research efforts to identify new treatments and therapies, and ultimately, a cure.
P.O. Box 643
Orchard Park, NY 14127
Tel: Orchard Park