[Studies on the molecular mechanism of GM(2) gangliosidosis].

To study the molecular mechanism of GM(2) gangliosidosis.,The skin fibroblasts from 4 patients with GM(2) gangliosidosis were subjected to culture. Enzyme activities assay, Western blot and immunocytochemical analysis were performed using the cultured fibroblasts.,The hexosaminidase (Hex) activities of 4 patients with GM(2) gangliosidosis were significantly decreased. The activities were 12% 3% 15% and 6% of control values, respectively. Western blot analysis indicated that the amount of Hex mature alpha- and beta- subunits (alpha m, beta m) was decreased in cells from patients 2 and 3, but only decreased alpha m was found in patient 1 and both alpha m and beta m were normal in cells from patient 4. Immunocytochemical analysis revealed the accumulated GM(2) ganglioside in cells from patients 1-4.,The pathogenesis of GM(2) gangliosidosis was associated with deficiency of Hex alpha m and beta m and GM(2) activator caused by HEXA, HEXB and GM(2)A gene mutations.