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; ding the patient galactose results in the elevation of blood glucose to normal levels; the administration glucagon fails to generate hyperglycemia; biochemical examination of liver glycogen reveals a normal glycogen structure 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

Ans.) If the mentioned patient is given glucose, it rapidly enhances the blood glucose level followed by a normal return to fasting level. But on the other hand, if the patient is given galactose, it fails to generate hyperglycemia (increased level of blood glucose). This is due to the fact that galactose can not be taken directly by the cells as at first it is converted into glucose. Therefore, galactose does not able to induce hyperglycemia.

Usually, people suffering from GSD have following symptoms-

Type of Glycogen Stoarge Disease - There is several different kind of glycogen storage disease. Few of them detailed below -

Glycogen Stoarge Disease I (Gierke disease) – In this, patient suffers from the lack of the enzyme Glucose-6-Phosphatase.

Glycogen Stoarge Disease III (Cori disease): It occurs due to deficiency of the debrancher enzyme that eventually causes the body to form glycogen molecules that have an abnormal structure which prevents the glycogen from being broken down into free glucose.

Glycogen Stoarge Disease IV (Amylopectinosis) - In this type of GSD, there is no increase in glycogen in the cells. Actually, glycogen build up in the tissue because in this ailment there no branching enzyme.