[P1-161] A Chinese boy with hypoglycemic encephalopathy due to fructose-1,6-bisphosphatase deficiency and two novel mutations in his FBP1 gene
Fructose-1,6-bisphosphatase deficiency is a rare autosomal recessive disease caused by the FBP1 gene mutations. Hypoglycemia, ketosis and lactic acidosis usually occur when the patients took a lot of fruit, longtime fasting or acute infectious illness due to gluconeogenetic pathway deficiency leading to encephalopathy and liver damage. In this study, the clinical and laboratory findings of a Chinese case were investigated. The boy visited us because of encephalopathy and liver damage. He disliked fruit and sweet food. When he was 1 year and 3 months old, he presented with vomiting, diarrhea and abdominal pain after eating melon. During the age of 1 to 2 years, four times episodes of vomiting, diarrhea, and coma after eating fruits or with a cold were recorded. When he was 2 years and 5 months, he had vomiting, coma, seizures and fever just half an hour after eating a lot of fruit. Hypoglycemia (0.52 to 2.3 mmol/L), metabolic acidosis, ketosis, liver damage and brain edema were observed. After treatment, his general condition improved. But he still have seizures and spastic paralysis. Two novel heterozygous mutations, c.974T>A and c.755A>T, were detected on his FBP1 gene, supporting the diagnosis of fructose-1,6-bisphosphatase deficiency. Fructose-1,6-bisphosphatase deficiency is a rare gluconeogenesis defect. The diagnosis of the patients is usually difficult, while the prognosis is good in most cases by adequate medical intervention. Fructose-restricted diet and avoiding long-time fasting in stable stage, and glucose administration in acute period are keys to improve the outcome of the patients.