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All Diseases > Sanfilippo Syndrome D
Sanfilippo Syndrome D (MPS IIID)
Alternative Names: Mucopolysaccharide Storage Disease Type III D; Mucopolysaccharidosis Type III D; Sanfilippo Disease, Sanfilippo Syndrome Type D
Disease Category: Lysosomal Diseases
A rare, inherited, lysosomal disorder, caused by a missing or abnormal enzyme that cannot break down heparan sulfate (a complex sugar molecule containing sulfate). This disease is one of four types (A, B, C, and D), each caused by different mutated genes. Some symptoms include psychomotor (mental and motor skill) regression, behavioral and sleep problems, hirsutism (excessive hair growth), seizures, unsteady gait, and vision and hearing loss.