Infantile sialic acid storage disease in two siblings.

Abstract

Infantile sialic acid storage disease (ISSD: McKusick 26992) is a rare disorder related to Salla disease (McKusick 26874) and sialuria (McKusick 26992). The disorder is caused by progressive accumulation of free sialic acid within lysosomes due to defective efflux (Renlund et al., 1986). This is probably caused by defective transport across the lysosomal membrane (Mancini et al., 1986). Free sialic acid content of tissues is elevated and there is hypersialuria (Stevenson et al., 1983).