[Mass-screening for acid mucopolysaccharidosis using urine samples by modified HCl-albumin turbidity method]

To establish a method for screening acid mucopolysaccharidosis (AMPS), the HCl-albumin turbidity method was reexamined and modified for semiquantitative analysis. Mucopolysaccharide samples and HCl-albumin in buffer solution were incubated at 37 degrees C for 30 minutes, and the optical density at 600 nm (OD 600) of the reaction mixtures were measured. When the same amount of the samples were tested, OD 600 of dermatan sulfate and hyaluronic acid were higher than that of keratan sulfate. When the cut-off point of OD 600 was set at 0.100 based on the values obtained from randomly selected subjects, only 3 of 328 urine samples (0.9%) showed value higher than the cut off value. The values in five patients with AMPS were all above 0.800 without overlapping those of the control subjects. These results suggest that mass-screening for AMPS using urine sample is possible by the partially modified HCl-albumin turbidity method with the cut-off point of OD 600 set at 0.100.