[Chance and discovery in research on the cause of infantile amaurotic idiocy].

Infantile amaurotic idiocy-the classical type known as "Tay-Sachs disease" -is the consequence of the accumulation of a ganglioside and a closely related derivation in the human brain. The accumulation of both substances is due to a genetically induced deficiency of their common catabolic enzyme system. K. Sandhoff discovered three enzymic variants of the disease, which, taken together, did not reveal any apparent causal relationship between enzymic defect and substrate accumulation. The role of chance and discovery in finding the three variants as well as in the elucidation of their causes is described.