Sanfilippo syndrome

Sanfilippo Syndrome (MPS III)
Other names	Mucopolysaccharidosis III; MPS III
12-year-old girl displaying characteristic facial features of Sanfilippo syndrome type A
Pronunciation	/ˌsænfɪˈliːpoʊ/ SAN-fil-EE-poh
Specialty	Medical genetics
Symptoms	Progressive physical disability; hyperactivity; dementia; loss of mobility
Usual onset	Birth; symptoms usually become apparent between ages 2 and 6
Duration	Lifelong
Types	Sanfilippo syndrome types A, B, C, and D
Causes	Inherited enzyme deficiency
Diagnostic method	MPS urine screen (typically the initial test), genetic testing, or blood enzyme assay[1]
Differential diagnosis	Autism spectrum disorder[2]
Prognosis	Lifespan is reduced; survival into adolescence or early adulthood
Frequency	1 in 70,000[3]

Sanfilippo syndrome, also known as mucopolysaccharidosis type III (MPS III), is a rare autosomal recessive lysosomal storage disease that primarily affects the brain and spinal cord. It is caused by a buildup of large sugar molecules called glycosaminoglycans (GAGs, or mucopolysaccharides) in the body's lysosomes.

Affected children generally do not show any signs or symptoms at birth, although some early indicators can be respiratory issues at birth, large head size, and umbilical hernia.^[4] In early childhood, they begin to exhibit signs of developmental disability and loss of previously learned skills. In later stages of the disorder, they may develop seizures and movement disorders. Patients with Sanfilippo syndrome usually live into adolescence or early adulthood.^[5]