Sanfilippo syndrome (mucopolysaccharidosis type III, MPS III) is a progressive 
disorder in which patients are characterized by severe central nervous system 
degeneration together with mild somatic disease. MPS III results from a 
deficiency in one of the four enzymes involved in the heparan sulfate 
degradation, with sulfamidase (SGSH), α-N-acetylglucosaminidase (NAGLU), 
acetyl-coenzyme A: α-glucosaminide N-acetyltransferase (HGSNAT), and 
N-acetylglucosamine-6-sulfatase (GNS) being deficient respectively in MPS IIIA, 
MPS IIIB, MPS IIIC and MPS IIID. Mutation screening using PCR 
reaction/sequencing analysis on genomic DNA fragments was performed in seven 
Tunisian index cases with MPS IIIA, three with MPS IIIB and two with MPS IIIC. 
QMPSF (Quantitative Multiplex PCR of Short fluorescent Fragments) analysis was 
developed for the detection of genomic deletions and duplications in the SGSH 
gene. These approaches allowed the identification of 11 mutations, 8 of them 
were novel including a mutation involving the start codon (p.Met1?), one small 
duplication (p.Leu11AlafsX22), one small deletion (p.Val361SerfsX52) and a large 
deletion of exon 1 to exon 5 in the SGSH gene, one missense mutation 
(p.Pro604Leu) and one nonsense mutation (p.Tyr558X) in the NAGLU gene and, 
finally, one missense mutation (p.Trp627Cys) and one nonsense mutation 
(p.Trp403X) in the HGSNAT gene.