[Sanfilippo Syndrome]

Sanfilippo syndrome (mucopolysaccharidosis type III) is a lysosomal disorder caused by a defect in the catabolism of heparan sulfate. Mucopolysaccharidosis type III is the most common type of all mucopolysaccharidoses. The pathogenic basis of the disease consists of the storage of undegraded substrate in the central nervous system. Progressive cognitive decline resulting in dementia and behavioural abnormalities are the main clinical characteristics of Sanfilippo syndrome. Mucopolysaccharidosis type III may be misdiagnosed as otherforms of developmental delay, attention deficit/hyperactivity disorder and autistic spectrum disorders because of lack of somatic symptoms, presence of mild and atypical forms of the disease. Patients with Sanfilippo syndrome may have comparatively low urinary glycosaminoglycans levels resulting in false negative urinary assay. Definitive diagnosis is made by enzyme assay on leucocytes and cultured fibroblasts. There is currently no effective treatment of mucopolysaccharidosis type III, though ongoing researches of gene, substrate reduction and intrathecal enzyme replacement therapies expect getting curative method to alter devasting damage of central nervous system in near future.