Lysosomal sialidase deficiency: increased ganglioside content in autopsy tissues of a sialidosis patient.

Organs obtained at autopsy from a patient with sialidosis were analyzed for 'bound' sialic acid and their ganglioside and neutral glycolipid patterns determined. The water-soluble bound sialic acid was increased between 10- and 17-fold in visceral organs, but only about 2-fold in the brain, when compared to normal controls. Lipid-bound sialic acid was increased up to 8-fold in visceral organs due to elevated amounts of gangliosides GM3, GD3 and probably GM4 and LM1, whereas the brain showed no deviation from controls. An alteration of the neutral glycolipid pattern was also observed. The results indicate an impaired catabolism of gangliosides in sialidosis in addition to that of sialyloligosaccharides and sialoglycoproteins.