GM1-gangliosidosis: accumulation of ganglioside GM1 in cultured skin fibroblasts and correlation with clinical types.

Uptake of radioactivity from 14C-galactose into gangliosides by cultured skin fibroblasts was studied. GM3 was the major ganglioside in control human fibroblasts. An increase of GM1 was demonstrated in GM1-gangliosidosis fibroblasts. The degree of GM1 accumulation was correlated with the clinical types of this disease. The fibroblasts from an infantile-type patient showed a marked increase of GM1. In late-onset types the amount of total gangliosides was only slightly increased, but the distribution of individual gangliosides was definitely abnormal; a relative increase of GM1 was demonstrated in these cases. GM1 beta-galactosidase activities were not detectable in either infantile or late-onset cases.