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There are 7 different Mucopolysaccharidosis metabolic disorders categorized by the type of enzyme that is missing.


Mucopolysaccharidosis MPS II, also known as Hunter Syndrome, is a rare lysosomal storage disease (LSD) affecting 1 in 100,000 boys in the world (approximately 500 cases in the US). Children with MPS II have a specific mutation in their genes that do not allow their bodies to produce functioning enzymes called iduronate 2 sulfatase. These enzymes are essential in breaking down certain glycosaminoglycans (GAGs) called dermatan sulfate and heparan. GAGs are long chains of sugar molecules that build bones, cartilage, skin, tendons and many other tissues in the body, but they also need to be broken down and recycled in the cells. The accumulation of GAG leads to progressive damage throughout the body.


Babies with MPS seem normal at birth, but signs and symptoms can appear from ages 2 to 4 years old as more and more GAG accumulate in their cells.


Depending on the severity, common signs & symptoms of MPS II include:

  • Heart murmur

  • Inguinal & umbilical hernias

  • Frequent ear and upper respiratory infections

  • Chronic runny nose

  • Obstructive sleep apnea

  • Course facial features (full lips, large rounded cheeks, broad nose, flat nose bridge, & enlarged tongue)

  • Large head

  • Thick hands

  • Pebble-like white growths on back and upper arms

  • Enlarged/swollen abdomen (due to enlarged liver and spleen)

  • Limited lung capacity

  • Cardiac/vascular heart disease

  • Hearing loss

  • Delayed speech/ speech loss

  • Poor vision

  • Delayed or inability to potty train

  • Short stature

  • Joint stiffness (limited range of motion)

  • Developmental delays

  • Loss of basic skills, functions, and intelligence (developmental regression)

  • Seizures

  • Fluid in the brain


It is sad that many doctors and health professionals are not fully aware about this disease. Since early intervention is essential in treating children with MPS, you would think that doctors would screen children for this disease, but that is not always the case. We need your help in spreading awareness about MPS to enhance the quality of life for our children in effort to find a cure.

What is MPS II?

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