A type of lysosomal storage disease that is often caused by a deficiency of a particular enzyme resulting in the accumulation of glycosaminoglycan heparan sulfate, and thereby leads to symptoms associated with the disease
Lysosomal storage disease is a collective term for the various metabolic disorders due to defects in lysosomal function resulting in an abnormal accumulation of toxic materials in the cell. One of them is Sanfilippo syndrome
Sanfilippo syndrome (also called mucopolysaccharidosis III, MPS-III) is a metabolic disorder involving the lysosomes. The lysosome is a cellular organelle that contains various enzymes essential in the breaking down of certain biomolecules. A genetic defect such as a pathologic mutation could lead to the insufficiency of the production of a particular lysosomal enzyme. In Sanfilippo syndrome, the enzyme necessary for the breaking down of heparan sulfate is insufficient or dysfunctional. For instance, a defect in the SGSH gene could affect the production of a functional heparan N-sulfatase. This could lead to MPS-III A. Another gene is NAGLU gene, which codes for N-acetyl-alpha-D-glucosaminidase. This is associated with MPS-III B. A defective gene, HGSNAT, coding for acetyl-CoA:alpha-glucosaminide N-acetyltransferase, is the one involved in MPS-III C. A pathologic mutation in GNS gene that codes for N-acetylglucosamine-6-sulfatase leads to MPS-III D.
Sanfilippo syndrome is inherited in an autosomal recessive pattern. The condition is named after the first to describe it, i.e. Sylvester Sanfilippo, a pediatrician.