Sir.—Fructose - 1,6 - diphosphatase (FDPase, EC 220.127.116.11) deficiency was first described in 1970.1 More than 40 patients have been described since then,2-6 and probably more will be diagnosed as the awareness of this disorder increases among clinicians. Most cases were reported in young patients, and although prognosis in these cases seemed favorable, follow-up to adulthood is still lacking.
The diagnosis of FDPase deficiency has usually been established by liver biopsy, since enzyme activity is undetectable in cultured skin fibroblasts and is extremely low in white blood cells of normal subjects.3
Herein we present a 20-year follow-up of a patient known to suffer from FDPase deficiency. Enzyme activity in the patient and his family were determined from an intestinal tissue specimen.
Patient Report.—A 22-year-old man, the first child of non-consanguineous parents of Jewish-Vemenite extraction, had normal growth and development until 20 months of age, when an intercurrent