“…Both compounds are shown to have considerable influence on glomerular function (Brenner et aI., 1978). In ISSD --a defect in a proton-driven transport system for free sialic and glucuronic acid (Mancini et al, 1989, Tietze et al, 1989) --other causes for the development of a nephrosis should be present, since all steps in the metabolism of free sialic acid, including its biosynthesis in the cytosol, its incorporation into glycoproteins and glycolipids and its liberation from these compounds in the lysosomal compartment, were shown to be normal (Hancock et al, 1983;Paschke et al 1986aPaschke et al , 1987Renlund et aI, 1983Renlund et aI, , 1986aMendla et al, 1988).…”