More specifically, Sanfilippo syndrome is an autosomal recessive LSD caused by deficiencies in one of four enzymes involved in heparan sulfate degradation—heparan N-sulfatase (SGSH, type A), α-N-acetylglucosaminidase (NAGLU, type B), acetyl-CoA:α-glucosaminide N-acetyltransferase (HGSNAT, type C), or N-acetylglucosamine-6-sulfatase (GNS, type D) [13]. This evidence concerns the gene GNS and mucopolysaccharidosis type 3.