Hunter Syndrome and Hurler Syndrome

What is it?

Hunter Syndrome is a rare genetic metabolic disorder, also called mucopolysaccharidosis II or MPS II. People who suffer from Hunter syndrome do not produce enough enzyme called iduronate 2-sulfatase. The enzyme task is to break complex sugar molecules, resulting in accumulation of these molecules, which leads to organ damage. The affected organs may include the bones, tendons and brain. The result of this condition results in permanent, progressive damage affecting appearance, mental development, organ function and physical abilities. The condition is passed along in the X-linked inheritance pattern, meaning it nearly always occurs in males. T Symptoms may vary, depending on the severity of the disease, but symptoms usually start between the ages 2-4. Hunter syndrome complications may include respiratory complications such as chronic ear and sinus infections, respiratory infections, pneumonia, sleep apnea. Cardiac complications may include heart valve defect, heart failure, aortic narrowing and elevated blood pressure. Skeletal and connective tissue complications may include growth delay, pain, physical malformation, stiffness,irregularly shaped vertebrae and spines, ribs, arms, fingers, legs, and pelvises and hernias. Nervous system complications may include vision problems, headaches, mental state alterations, hyperactivity, behavioral problems and seizures.

Hurler syndrome is a rare genetic lysosomal storage disease, and it is the most severe form of mucopolysaccharidosis 1. People who suffer from Hunter syndrome do not produce any enzyme called alpha-L-iduronidase resulting in accumulation of dermatan sulfate and heparan sulfate, which leads to organ damage. The affected organs may include the bones, heart, lungs and brain. The result of this condition results in permanent, progressive damage affecting appearance, mental development, organ function and physical abilities. The condition is transmitted in autosomal recessive inheritance pattern. Symptoms may vary, depending on the severity of the disease, but symptoms usually start in the first year of life. Hurler syndrome complications may include respiratory complications, cardiac complications such as valvular abnormalities and cardiomyopathy, heart failure. Skeletal complications may include growth delay, pain, physical malformation, stiffness and irregularly shaped vertebrae and spines. Nervous system complications may include developmental delay and hydrocephalus.

Hunter syndromes distinguished from Hurler syndrome by an X-linked recessive inheritance, longer survival, lack of corneal clouding, the characteristic papulonodules, and the different biochemical defect.