A 6 month child presents with episosdes of vomitting after ingesting fruit juice. Which of following enzyme deficiency is likely ?
The condition is hereditary fructose intolerance,an autosomal recessive inborn error of metabolism,due to defect in aldolase-B or fructose-1-phosphate aldolase.Hence,fructose -1-phosphate cannot be metabilised.This is seen when sucrose containing fructose(eg.,fruit juices) is introduced in the diet of infants,usually around 6 months of age.Accumulation of fructose-1-phosphate will inhibit glycogen phosphorylase.This leads to accumulation of glycogen in liver and associated hypoglycemia.Vomiting and loss of appetite are seen.The infants often fail to thrive.Hepatomegaly & jaundice may occur.If liver damage progresses,death will occur.Withdrawal of fructose(fruit juices)from the diet will immediately relieve the symptoms. Reference:Textbook of biochemistry-DM Vasudevan,6 th edition,page no:120.
Aldolase B
Fructokinase
Glucose 6 phosphatase
Hexokinase
Metabolic disorders