[Fructose-1,6-diphosphatase deficiency. Clinical aspects and diagnosis based on a case report].

In a 2-year-old boy the enzyme defect of fructose-1,6-diphosphatase deficiency could be demonstrated in liver tissue, jejunal mucosa and leukocytes. During the neonatal period the boy had suffered from transient metabolic acidosis and hypoglycemia. At the age of 2 years, during a febrile infection, he developed a hyperkinetic-hypotonic syndrome, which disappeared by fructose-free diet and avoidance of prolonged periods of fasting.