Screening test for urinary glycosaminoglycans and differentiation of various mucopolysaccharidoses

The Ames MPS paper spot test and the cetylpyridinium chloride (CPC)-citrate turbidity test were used to detect urinary glycosaminoglycans (GAGs) as screening tests for the diagnosis of mucopolysaccharidoses (MPSs). The simplicity and reliability of these two methods were evaluated. The MPS paper spot test correlated more closely with the carbazole test than did the CPC-citrate turbidity test. The monodimensional electrophoresis of Cappelletti et al was also used to screen the subtypes of MPSs using differences in electrophoretic patterns. MPS VII cannot be distinguished from normal by its electrophoretic pattern, but can be detected by the MPS paper spot test. Therefore, the MPS paper spot test combined with monodimensional electrophoresis can detect these subtypes of MPSs (MPS I-II, III, IV, VI, VII). Since only 20 ml of random urine is needed and the result can be obtained with complete reliability in only 7 hours, this screening test appears to be useful for the early diagnosis of MPSs.