About Morquio A

The following information was provided by the MPS Society.

MPS IV is a mucopolysaccharide disease known as Morquio or Morquio-Brailsford syndrome. MPS IV has a wide range of symptoms that vary in severity and can be managed and treated with enzyme replacement therapies. There is no cure for MPS IV.

What causes the disease?

Mucopolysaccharides are chains of sugar molecules used to build connective tissues in the body.

• “muco” refers to the thick jelly-like consistency of the molecules
• “poly” means many
• “saccharide” is a general term for a sugar molecule

The body constantly replaces used materials and breaks them down for disposal. MPS IV patients are missing an enzyme essential to breaking down the mucopolysaccharide keratan sulfate. These materials remain stored in the body’s cells, causing progressive damage. Babies may show little sign of the disease, but as cells sustain damage, symptoms start to appear.

How common is MPS IV?

MPS IV is one of the rarest of the MPS diseases in the United States. Reliable incidence figures are not available, but estimates find the disease in 1 in 200,000 to 300,000 individuals.

How is the disease inherited?

MPS IV is caused by a recessive gene. There is a one in four chance with every pregnancy that the child will inherit the defective gene from each carrier parent and will be affected with the disease. There is a two in three chance that unaffected brothers and sisters of children with MPS IV will be carriers.

Is there a cure for MPS IV?

There is no cure for MPS IV.