Hunter's syndrome is also known in medical literature as mucopolysaccharidosis type II, MPS disorder II, and MPS II

It is an X-linked recessive genetic disease caused by a deficiency of the enzyme iduronate sulfate sulfatase (also known as sulfoiduronate sulfatase), which breaks down dermatan sulfate and heparan sulfate, two types of mucopolysaccharides (complex carbohydrates).

Consequently, the mucopolysaccharides accumulate in the cells of the body and cause organ and tissue damage. Patients have the two types of sulfates in their urine and suffer from skeletal defects, retinitis pigmentosa (a form of progressive blindness), skin lesions, progressive deafness, brain damage, and heart problems. Characteristic symptoms include a coarse face, enlargement of the liver and spleen, and mental retardation in children with the disease.

There are mild and severe forms of the syndrome and presently there is no cure; however, stem cell transplants from donor bone marrow or umbilical cord blood can help some children. In the U.S., clinical trials for experimental enzyme replacement therapies are under way. Other symptoms are treated as they appear. Hunter's syndrome is the most common of a number of related rare genetic mucopolysaccharide disorders. The second most common type is Hurler's syndrome

This disorder was named after a researcher named C. A. Hunter, who published a paper entitled "A rare disease in two brothers" in Proceedings of the Royal Society of Medicine in 1917.

From the science dictionary at