SGSH and mucopolysaccharidosis type 3A: MPS IIIA is caused by mutations in the lysosomal hydrolase gene, N-sulfoglucosamine sulfohydrolase (SGSH), which produces sulphamidase that normally catalyses the degradation of the glycosaminoglycan (GAG), heparan sulphate (HS), to monosaccharides and inorganic sulphate for recycling in the cell [4].