Sanfilippo Syndrome (MPS III) is a recessive autosomal genetic disease. It occurs in approximately 1 in 70,000 births. Children with Sanfilippo Syndrome are missing an essential enzyme needed to break down a specific long sugar chain (glycosaminoglycan or GAG) in the body called heparan sulfate. Because heparan sulfate cannot be recycled by the body, it accumulates in the lysosomes of all cells causing progressive damage to the central nervous system.
Babies and young children with Sanfilippo Syndrome appear normal. Symptoms begin to appear as more and more heparan sulfate builds up in the cells of the body.
There are 3 stages in the disease.
In the first stage (starting around 2-4 years of age), a developmental delay becomes apparent after an initial period of normal development.
In the second stage (starting around 3-5), the child becomes hyperactive, develops the need to chew on everything, has sleep difficulties and loses language skills. This progressive mental deterioration leads to severe dementia.
In the third stage (starting around 8-11), behavior issues diminish as the child loses volition. Children lose all motor skills and become completely dependent, even gradually losing the ability to chew and swallow. Seizures are common.
There is no treatment of cure for Sanfilippo Syndrome. Life expectancy varies. Many children die in their teens or early twenties.