Mucopolysaccharidoses

[Marquetta]

Mucopolysaccharidoses are a type of lysosomal storage disorder in which complex sugar molecules are not broken down normally and accumulate in harmful amounts in body tissues. The result is a characteristic facial appearance and abnormalities of the bones, eyes, liver, and spleen, sometimes accompanied by intellectual disability. Mucopolysaccharidoses occur when parents pass the defective genes that cause these disorders on to their children.

Mucopolysaccharidoses occur when the body lacks enzymes needed to break down and store complex sugar molecules.
Typically, symptoms include short stature, hairiness, stiff finger joints, and coarseness of the face.
The diagnosis is based on symptoms, a physical examination, and blood tests.
Although a normal life span is possible, some types cause premature death.
Treatment may include lifelong enzyme replacement therapy, and sometimes a bone marrow transplant.

There are different types of inherited disorders. In many hereditary metabolic disorders, both parents of the affected child carry a copy of the abnormal gene. Because usually two copies of the abnormal gene are necessary for the disorder to occur, usually neither parent has the disorder. Some hereditary metabolic disorders are X-linked, which means only one copy of the abnormal gene can cause the disorder in boys. (See also Overview of Hereditary Metabolic Disorders.)
Complex sugar molecules called mucopolysaccharides (glycosaminoglycans) are essential parts of many body tissues. In mucopolysaccharidoses, the body lacks enzymes needed to break down (metabolize) and store mucopolysaccharides. As a result, excess mucopolysaccharides enter the blood and are deposited in abnormal locations throughout the body.