AGE-RELATED REFERENCE VALUES FOR URINARY-EXCRETION OF SIALIC-ACID ANDDEOXYSIALIC ACID - APPLICATION TO DIAGNOSIS OF STORAGE DISORDERS OF FREE SIALIC-ACID

We have established by HPLC age-related reference intervals for sialic acid urinary excretion in 364 control individuals to assist in evalua ting the clinical significance of the free sialic acid concentration i n urine. In addition, an HPLC method for quantitative analysis of free deoxysialic acid was developed, and age-related reference intervals f or excretion of this compound in urine were established. In patients w ith storage disorders of free sialic acid (n = 11) the sialic acid exc retion was increased 2- to 35-fold, compared with the mean value of th e control subjects in the corresponding age group, and exceeded the in terval in each case. The excretion of deoxysialic acid was within the reference interval in all of the patients, indicating that its metabol ism was not affected in the disorders. The age-related reference value s assist in evaluating the excretion of free sialic acid in the diagno sis of storage disorders of free sialic acid, especially in young chil dren.