Glycogen Storage Disorders

Question 1

Von Gierke (Type I)

Answer 1

Glucose-6-phosphatase deficiency results in hypoglycemia and muscles resorting to anaerobic glycolysis to generate ATP and the production of large amounts of lactic acid leading to lactic acidosis; Sx: Hepatomegaly, ketosis, hyperlipidemia

Question 2

Pompe Disease (Type II)

Answer 2

Lysosomal glucosidase aka ACID MALTASE deficiency; Sx: Cardiomegaly & hepatomegaly

Question 3

Cori Disease aka Forbe’s Disease (Type III)

Answer 3

Debranching enzyme def.; Sx: Hepatomegaly, nl blood glucose & lipids

Question 4

Andersen’s Disease (Type IV)

Answer 4

Branching enzyme def.; Sx: hepatomegaly, cirrhosis & liver failure

Question 5

McArdle Disease (Type V)

Answer 5

Muscle Glycogen Phosphorylase def.; Sx. leads to impaired glycogen breakdown and thus muscle weakness due to inability to mobilize glycogen stores; nl lactate

Question 6

Hers Disease (Type VI)

Answer 6

Hepatic Glycogen Phosphorylase def.; Sx: Hepatomegaly, less severe hypoglycemia than Von Gierke, lipidemia & acidosis

Question 7

Tarui Disease (Type VII)

Answer 7

Muscle PFK-1 (muscle & erythrocytes) OR Glycogen Synthase def.; Sx: muscle weakness & craming during excercise, NO glycogenesis hypoglycemia, accumulation of lactate (even w/o lactate spike/rapid increase)