Consider a patient with the following clinical findings Fast

Consider a patient with the following clinical findings: Fasting blood glucose level of 25 mg per 100ml (normal 80-100mg per 100ml); feeding the patient glucose results in a rapid elevation of blood glucose level, followed by a normal return to fasting levels; feeding the patient galactose or fructose results in the elevation of blood glucose to normal levels; the administration of glucagon fails to generate hyperglycemia; biochemical examination of liver glycogen reveals a normal glycogen structure (5 pts).

Which of the enzyme deficiencies in the glycogen storage diseases described in chapter 12, page 381 of your textbook could account for these clinical findings? Briefly explain how you came to this conclusion.

What additional experiments would you conduct to provide a specific diagnosis for this patient?

Solution

Que-1:

The above patient has deficiency of \"glycogen phosphorylase\" so that even glucagon is administered glycogen debranching has not occurred because normally glucagon is going to stimulate \"second messenger system\" via G-protein coupled receptors in liver cells to trigger \"debranching of glycogen\" in the presence of enzyme glycogen phosphorylase. However, deficiency of this enzyme is leading to no activity of \"adenylate cyclase\" through glucagon and no normal level fo glucose even in fasting stage