title: [Genetic study of GM2 gangliosidosis (Tay-Sachs and Sandhoff) by the study of the hexosaminidases of the Sandhoff-rodents hybrids (mouse and hamster)].
abstract: The electrophoretic pattern of human fibroblast extracts displays three bands (cathode to anode) of hexosaminidase: Hex B, Hex A, Hex C in normal strains, only one B band in Tay-Sachs strains, and only one C band in Sandhoff strains. The author's observations on rodent-Sandhoff cellular hybrids agree with the hypothesis made by others: Hex B = (beta beta)n; Hex A = (alpha beta)n; and Hex B = (alpha alpha) n. The mutation occurred in the alpha chain in Tay-Sachs disease and in the beta chain in Sandhoff disease. When mannose phosphate isomerase (MPI) is present, and therefore Hex C because of the well known MPI - Hex C synteny, a new hexosaminidase band called "Hex A fast" is seen in Sandhoff-hamster hybrids, while a "Hex A like" band is seen in Sandhoff-mouse hybrids. Both bands are absent from parental cells. It is suggested that "Hex A fast" and "Hex A like" are human-rodent hybrid hexosaminidases: "Hex A fast" = (alpha beta')n; "Hex A like" = (alpha beta's)n with the assumption that hamster HB' = (beta' beta')n and mouse Hex B'S = (beta's beta's)n. The specific anti Hex A = anti (alpha beta); the non-specific anti Hex A = anti Hex B = anti (beta); the anti (alpha) would be absent or weak. This explains the reactivity of the anti-Hex A against Hex A and Hex B, but not against Hex C.
mesh_terms: D000818:Animals; D006224:Cricetinae; D004586:Electrophoresis; D005347:Fibroblasts; D005732:Gangliosides; D006596:Hexosaminidases / Q000032:analysis* / Q000302:isolation & purification; D006801:Humans; D006822:Hybrid Cells / Q000201:enzymology*; D008064:Lipidoses / Q000201:enzymology; D051379:Mice; D009154:Mutation; D013106:Sphingolipidoses / Q000201:enzymology*
chemical_list: D005732:Gangliosides; D006596:Hexosaminidases
vernacular_title: Contribution à l'étude génétique des gangliosidoses GM2 (Tay-Sachs et Sandhoff) par l'étude des hexosaminidases des hybrides Sandhoff-rongeurs (souris et hamster)