Sanfilippo disease is a mucopolysaccharide disease also known as MPS lll. It takes its name from Dr. Sanfilippo who was one of the doctors from the United States who described the condition in 1963. To date four different enzyme deficiencies have been found to cause Sanfilippo disease and so the condition is described as type A,B,C or D. Type A is the most common form found in most populations. MPS lllA is missing the enzyme heparan N sulphatase MPS lllB is missing alpha-N-acetylglucosaminidase MPS lllC is missing acetyl-CoA: alpha-glucosaminide acetyltransferase MPS lllD is missing N-acetylglucosamine-6-sulphatase However it is important to note that there are no significant clinical (physical) differences between the different subtypes of MPS III, although there have been some very mild cases of the B form where the sufferers have remained relatively unaffected into adult life. The latest understanding is that some people seem to produce some enzyme activity which helps to slow down the progression of the disease while those with more severe symptoms appear to have no enzyme activity at all


There is a continuous process in the body of replacing used materials and breaking them down for disposal. Children with Sanfilippo disease are missing an enzyme which is essential in cutting up the used mucopolysaccharides. The incompletely broken down mucopolysaccharides remain stored in cells in the body causing progressive damage. Babies and small children may show little sign of the disease but, as more and more cells become damaged, symptoms start to appear


If you already have a child with Sanfilippo disease it is possible to have tests during a subsequent pregnancy to find out whether the baby you are carrying is affected. It is important to contact your doctor as soon as you suspect you may be pregnant if you wish tests to be arranged. If you have any difficulties please contact the Society without delay