Question

A previously healthy 2-month-old female presents with jittery spells several hours after breastfeeding. Her mother reports she has not given the baby anything to eat other than breastmilk since birth. The baby has only recently been sleeping for more than 2 hours between feedings and that’s when the mother reports these symptoms started. Laboratory results are consistent with hypoglycemia (low blood glucose) but are otherwise unremarkable. ​Epinephrine is administered and there is no increase in blood glucose but there is an increase in blood lactate​​ (Hint: think of what pathways would be activated by this hormone).

Physical exam reveals a liver edge 4 cm below the right costal margin. Percussion of the right chest and abdomen confirms hepatomegaly (enlarged liver).

Blood glucose levels increase after breastfeeding but she cannot maintain blood glucose levels within a normal range during fasting.

Based on the information above, which of the following is the most likely diagnosis of this patient? Describe why the other options are not the best answer.

a) Hereditary fructose intolerance

b) Galactosemia

c) Glycogen storage disease (inability to use glycogen)

d) Glucose 6-phosphate dehydrogenase deficiency

Answer 1