An 6 month old infant presented with vomiting upon weaning with fruit juices.Till now he was on exclusive breast
feeding. What is the probable enzyme deficiency?
A. Hexokinase
B. Aldolase B
C. FructoKinase
D. Glucose 6 Phosphatase
Biochemical defect
Deficiency of Fructose-1,6-Bisphosphate Aldolase (Aldolase B)
Deficiency of this enzyme activity causes a rapid accumulation of fructose-1-phosphate and
initiates severe toxic symptoms when exposed to fructose.
Clinical manifestations
Patients with HFI are asymptomatic until fructose or sucrose (table sugar) is ingested (usually from fruit, fruit juice,
or sweetened cereal).
Symptoms may occur early in life, soon after birth if foods or formulas containing these sugars are introduced into
the diet.
Early clinical manifestations resemble galactosemia and include jaundice, hepatomegaly, vomiting, lethargy,
irritability, and convulsions,hypoglycemia .
Acute fructose ingestion produces symptomatic hypoglycaemia