Eleven cases of hereditary fructose intolerance in one Swiss family with a pair of monozygotic and of dizygotic twins.

A large pedigree of one Swiss family with 11 cases of hereditary fructose intolerance (HFI) is presented, among them a pair of monozygotic twins with HFI and a pair of dizygotic twins one of whom had the disorder. The clinical course of undiagnosed babies with HFI at home is described. The case histories point out the importance of the mother's awareness of the situation since in none of the 11 cases the corrected diagnosis of HFI was made by a physician.