Discovered in 1963 by Dr. Sylvester Sanfilippo at the University of   Minnesota Medical School, MPS III is a autosomal recessive condition; meaning the erroneous gene copy is found on a non-sex (X/Y) gene and both parents must pass down thieir faulty copy to their child in order for the syndrome to become present.  The prevalence of Sanfilippo Syndrome with all its subtypes is 1 in 70,000, defining it as a rare disease.

Missing from children with MPSIII is an enzyme to break down heparan sulfate.  Resulting from the over accumulation of heparin sulfate within the cells is central nervous system deterioration.  This will become apparent through clinical symptoms of delayed speech, intellectual disabilities, extreme hyperactivity coupled with minimal sleep patterns and later on, seizures, swallow compromises and the loss of developmental milestones and physical independence.  MRI imaging often shows brain atrophy; with white matter abnormalities and ventricular enlargement.  Organs including the spleen and liver enlargement as well as hernia presentations may also be found.  The myriad of systems and level of involvement can vary from child to child along with its timeline.

Life expectancies vary with an average range between early adolescence to early adulthood.

1.  Mucopolysaccharidosis type III Genetics Home Reference. (2017, December 29). Retrieved January 01, 2018, from https://ghr.nlm.nih.gov/

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