Gangliosidosis with total hexosaminidase deficiency: Clinical, biochemical and ultrastructural studies and comparison with conventional cases of Tay-Sachs disease

Abstract

Biochemical studies were performed on brain biopsies, and ultrastructural studies on brain and liver biopsies from three children presenting clinically the infantile form of Tay-Sachs disease. Gangliosides were markedly increased both in grey and white matter, and consisted mainly of fraction GM2. In one case (patient 1), the amount of N-acetylaminotrihexosyl-ceramide, the asialo-residue of ganglioside GM2, was much larger than in the two other cases (patients 2 and 3). Enzyme studies performed on liver tissue disclosed, in patient 1, a nearly complete absence of the total hexosaminidase activity, which was within normal limits in the two other cases. Ultrastructural data in brain and liver were also different in the three cases. In patient 1, the lipid inclusions of the neurons, astrocytes and endothelial cells were markedly more pleiomorphic than in cases 2 and 3. In the liver of patient 1, hepatocytes and, in a lesser degree, Kupffer cells were full of lipid inclusions, whereas in the two other cases, only a small number of lipid lamellar elements were present in a few cells.