Synonym: Sanfilippo syndrome

Etiology:
Disease
Mucopolysaccharidosis Type IIIA. Deficient enzyme: Heparan-sulfamidase
Mucopolysaccharidosis Type IIIB. Deficient enzyme: N-acetyl-alpha-glucosaminidase
Mucopolysaccharidosis Type IIIC. Deficient enzyme: N-acetyltransferase
Mucopolysaccharidosis Type IIID. Deficient enzyme: N-acetyl-glucosamin-6-sulfate-sulfatase

Gene:
Disease
Mucopolysaccharidosis Type IIIA. Gene: SGSH
Mucopolysaccharidosis Type IIIB. Gene: NAGLU
Mucopolysaccharidosis Type IIIC. Gene: HGSNAT
Mucopolysaccharidosis Type IIID. Gene: GNS

Mode of inheritance: Autosomal recessive

Phenotypes:

• Severe form
• Attenuated form

Leading symptoms:
Severe form
(Age of onset:  )

• Psychomotor development delay/ regression
• Behavioral disorder
• Hyperaktivity
• Sleep disorder
• Epilepsy
• Joint contractures

Attenuated form
(Age of onset: childhood/ adolescence)

• Loss of cognitive and motor skills
• Psychiatric symptoms

Diagnostics:

• Measurement of the activity of heparan-sulfamidase (Type IIIA), N-acetyl-alpha-glucosaminidase (Type IIIB), N-acetyltransferase (Type IIIC), N-acetyl-glucosamin-6-sulfat-sulfatase (Type IIID) in leukocytes or serum or plasma
• Molecular genetic analysis of the appropriate gene: SGSH, NAGLU, HGSNAT, GNS

Therapy:
Only symptomatic