Glycogen Storage Disease

Question 1

Severe fasting hypoglycemia, highly elevated glycogen in liver, inc TGs, inc uric acid + hepatomegaly

Answer 1

Von Gierke Disease (type I glycogen storage disease)

Question 2

Enzyme def in Von Gierke Disease

Answer 2

glucose-6-phosphatase

Question 3

Tx of Von Gierke

Answer 3

1. frequent oral glucose/cornstarch

2. avoid fructose and galactose

Question 4

Cardiomegaly, hyeprrophic cardiomyopathy, exercise intolerance, systemic findings (leading to early death)

Answer 4

Pompe Disease (type II)

Question 5

enzyme def in Pompe

Answer 5

lysosomal alpha, 1-4 glucosidase (acid maltase)

Question 6

Cori disease

Answer 6

milder form of type I (Von Gierke)

• normal blood lactate levels
• gluconeogenesis intact

Question 7

enzyme def in Cori disease

Answer 7

debranching enzyme (alpha 1,6 glucosidase)

Question 8

painful muscle cramps, myoglobinuria (red urine) w/ strenuous exercise, possible ARR

Answer 8

McArdle Disease (type V)

Question 9

enzyme def in McArdle

Answer 9

skeletal muscle glycogen phosphorylase (myophosphorylase)

Question 10

Tx McArdle Disease

Answer 10

typically blood glucose levels are fine

tx w/ Vit B6