An eight-month-old female infant presented with recurrent episodes of hypoglycemia, especially if time interval of feeding is increased. Dicarboxylic acid is present in the urine. Urine ketone bodies is negative. The child responded well to IV Glucose, less fat and more carbohydrate diet, frequent feeding. The child was diagnosed to be MCAD deficiency. What is the reason for hypoglycemia?
Ans. B. Lack of ATP to support gluconeogenesis* This is a case of MCAD deficiency.* Identifying features are:* Recurrent episodes of hypoglycaemia is time interval of feeding increased* Dicarboxylic acids in urine* Absence of ketone bodies in urine* Reasons for hypoglycemia are:* Due to MCAD deficiency, beta oxidation is affected. This is the source of ATP for gluconeogenesis, when glycogen stores are depleted. So lack of ATP is one reason* Due to lack of acetyl-CoA, which is released by beta oxidation. Acetyl-CoA is the activator of pyruvate carboxylase, one of the key enzymes of gluconeogenesis
Increased dicarboxylic acid inhibit glycogenolysis
Lack of ATP to support gluconeogenesis
Lack of acetyl-CoA to favour glycogenolysis
Glycogen stores are inadequate in infants
Carbohydrates