DiagnosticTest for Mucopolysaccharidosis. II. Rapid Quantificationof Glycosaminoglycan in Urine Samples Collected on a Paper Matrix

The direct 1,9-dimethylmethyleneblue (DMB) method for quantifyingsulfatedglycosaminoglycan(GAG) in urine (Clin Chem 1989;35:374-9) has been adapted to a convenient meansforsamplecollectionandtransportas a test to identify individualswith mucopolysaccharidosis(MPS) storage dis-eases. Results correlated moderately well (r = 0.85) with those of a commonlyused, but more laborious,quantitative method. In studying factors to maximize differentiationof pathological from normal values, we found that GAG excre-tion(expressedas milligramsGAG pergramcreatinine)fitsa logarithmic function with respect to age and vanes markedly belowage five years. This mustbe consideredindeveloping normative values and formingdiagnoses. Of 112 separate urine specimensobtainedfrom 41 MPS patientsrepresent-ing the major MPS diseases, glycosaminoglycanexcretio