Urinary excretion of a large amount of bound sialic acid and of under sulfated chondroitin sulfate A by patients with the Lowe syndrome.

Urine samples from two patients with the Lowe syndrome were analyzed for sialic acid and mucopolysaccharides. The sialic acid content, relative to the creatinine content, was 4--5 times higher in these patients' urine than in normal urine. Most of the sialic acid was found in unidentified glycoproteins of high molecular weight, but the levels of sialyllactose and free sialic acid were also elevated about 2 fold. A most remarkable finding was the excretion of undersulfated chrondroitin sulfate A without other mucopolysaccharides normally occurring in urine. It is suggested that a disorder in sulfation of mucopolysaccharides is etiologically implicated in the Lowe syndrome.