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 is this 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.