[Fructose 1,6-diphosphatase deficiency in 2 sisters].

The discovery of a fructose-1,6-diphosphatase deficiency in two sisters leads to the discussion of the various loading tests which are required for the diagnosis. The diagnosis may be discussed clinically with type I glycogenosis, and biologically with hereditary fructose intolerance. The specific characteristics of these disorders are analyzed as well as the problem of fructose induced hypoglucosemia. The failure of the treatment with folic acid in one of the cases leads to emphasize the suppression of prolonged fast in order to avoid acute accidents.