A urinalysis can show elevated levels of heparan sulfate in the urine. All four types of Sanfilippo syndrome show increased levels of GAGs in the urine; however, this is less true of Sanfilippo syndrome than other MPS disorders. Additionally, urinary GAG levels are higher in infants and toddlers than in older children. In order to avoid a false negative urine test due to dilution, it is important that a urine sample be taken first thing in the morning.
