Sanfilippo Syndrome


Sanfilippo Syndrome is a rare and catastrophic genetic disorder that takes its name from Dr. Sylvester Sanfilippo, one of the doctors who first described the condition in 1963. Sanfilippo Syndrome is a mucopolysaccharide disorder and is also known respectively as MPS III. It falls within a broader group of genetic disorders known as Lysosomal Storage Diseases. What these diseases share is an enzymatic defect which causes an accumulation of material within the cells of the body. The consequences vary greatly among the subgroups, ranging from a mild impact with a normal life expectancy to a severe and terminal outcome such as Sanfilippo Syndrome.

Children afflicted with Sanfilippo Syndrome are missing an essential enzyme that breaks down strings of a complex body sugar called heparan sulfate. The partially broken-down sugar, or mucopolysaccharide, accumulates in the brain and the body’s cells and tissue causing progressive damage. The storage process affects children’s appearances, bodily functions and development. Sanfilippo children tend to look alike and have similar health problems.

A Sanfilippo child appears normal at birth and develops within the range of normal for the first year or two, but as more and more cells become damaged symptoms begin to appear. Eventually, the build-up of muccopolysaccharides will cause hyperactivity, sleep disorders, loss of speech, mental retardation, dementia and finally death. Life expectancy for a child with Sanfilippo Syndrome is between 12 to 20 years.

To date four different enzyme deficiencies have been found to cause Sanfilippo. They are described as type A, B, C, or D. There is very little difference between the four types.

A couple, both of whom must carry the defective gene, have a 25% chance of conceiving an affected child, a 25% chance of conceiving a normal unaffected child and a 50% chance of conceiving a child who is a carrier like the parents.

It is estimated that Sanfilippo occurs 1 in 24,000 births. Based on this estimate there are approximately 200 children born with this disorder in the United States each year. Given the average lifespan, there are most probably thousands of families dealing with this in the USA alone. Since Sanfilippo does not appear to be more prevalent in one geographic area or in a particular ethnic group these numbers increase to the thousands (births) and tens of thousands (living) throughout the world.

There is currently no treatment or cure.

Note: Some of the above material was adapted from "Human Genetic Disease – A Layman's Approach" by Drs. Moremen and Malm (link no longer active)


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