Definition:
MPS VII or Sly syndrome is a rare disorder that results when an individual has very little or is missing the enzyme beta-glucuronidase. This enzyme is used in the lysosome to break down a complex string of sugars known as Glycosaminoglycans (GAGs), often referred to as mucopolysaccharides. In individuals inflicted with MPS VII, the GAG accumulates and results in symptoms of this disorder. GAGS are vital building blocks in the structure of the skin, bones and organs.

MPS VII is very rare, affecting approximately one in every 1,300,000 live births.

Symptoms:
The neonatal form of MPS VII is one of the few lysosomal storage disorders with clinical manifestations in utero or at birth. In this extreme case, the affected infant develops a condition known as hydrops fetalis in which the child retains unusually large amounts of fluid in his or her body.

As GAG accumulates the symptoms become more progressive.

There is no one hallmark sign or symptoms that characterizes MPS VII. The symptoms, which are widespread in onset, severity and in type, can manifest in early infancy, adolescence or during adulthood, depending upon how much GAG accumulates in the cells.

Coarse facial features including a bulging forehead, an enlarged tongue and lips and a flattened nose bridge are often seen in individuals inflicted with this disorder. Physical growth in height is significantly lower than average in affected individuals.

As the GAG and related materials accumulate in the brain, between one and three years of age, a slow deterioration of intelligence and mental capacities may appear. Some individuals with a mild form of MPS VII may be able to read and walk.

Chronic ear infections, hearing difficulties and sleep apnea are other common symptoms of this disease. Symptoms specific to the organs include an enlarged liver and/or spleen, distended abdomen, hernias and heart murmurs. Other symptoms may include difficulty breathing, noisy breathing, and an increase in sinus infections. Corneal clouding is a common symptom of MPS VII. Bowel problems including diarrhea and constipation are also common.

A poorly formed spinal cord, an unstable neck, scoliosis, stiff joints, stubby hands, thick skin and an excess of hair on the face and back may also occur.

Inheritance Patterns:
MPS VII is an autosomal recessive disorder.

Life Expectancy:
Life expectancy is younger than two to three months of age for children inflicted with an extreme case of MPS VII. Life expectancy for those with milder forms of MPS VII is varied: Some can live until their teenaged years while others can live to adulthood.

Diagnosis and Testing:
Two tests are used to determine whether a person has MPS VII. A urine measures the amount of GAG in the urine. Individuals with MPS VII have abnormally large amounts of GAG in their urine. An enzyme assay measures the amount of the enzyme, beta-glucuronidase in blood or tissue samples, confirming a diagnosis. Individuals with MPS VII have very low amounts of this enzyme in their cells.

Prenatal diagnosis is also available.

Treatment:
There is no cure for MPS VII, but there are many treatments that can be administered to delay symptom progression and to improve the quality of life in affected individuals.

Some parents find that putting their child on a diet reducing dairy, sugar and additives can improve gastrointestinal and hyperactivity symptoms experienced by affected children.

Physical therapy may improve joint flexibility and range of motion.

Surgical procedures may improve respiratory problems as well as chronic ear infections. Cornea transplant is also an effective treatment.

Patient Groups:
National MPS Society
4220 NC Highway 55, Suite 140
Durham NC, 27713
www.mpssociety.org
tel: (919) 806-0101
fax: (919) 806-2005
Barbara Wedehase, Executive Director
info@mpssociety.org