Electrophoretic examination of proteinuria in Lowe's syndrome and other causes of renal tubular Fanconi syndrome.

Urine samples from 26 patients with five different causes of renal tubular Fanconi syndrome were examined by zone electrophoresis on agarose gel and immunofixation. The tubular disorders associated with Lowe's syndrome, cystinosis, and idiopathic Fanconi syndrome exhibited urine protein electrophoretic characteristics that differentiated them from normal and from each other. In particular, Lowe's syndrome urine exhibited four discrete bands in the gamma globulin zone. Electrophoresis of urinary proteins may be useful in distinguishing among the different metabolic disorders causing renal tubular Fanconi syndrome.