Glycogen Storage Diseases Flashcards
What are the 4 types of Glycogen Storage Diseases?
Von Gierke Disease (type I)
Pompe Disease (type II)
Cori Disease (type III)
McArdle Disease (type V)
“Very Poor Carb Metabolism”
What can be used to identify glycogen within cells?
Periodic acid-Schiff Stain
(PAS)
What enzyme is deficient in Von Gierke Disease
(type I)?
Glucose-6-phosphatase
How does Von Gierke Disease typically present?
Fasting hypoglycemia
Increased Glycogen in liver and kidney
Hepatomegaly & Renomegaly
Increased Lactate, Triglycerides, Uric Acid
Is gluconeogenesis and glycogenolysis intact or impaired in Von Gierke Disease?
They are both impaired
(NOTE: in Cori disease, the milder form of Von Girke, gluconeogenesis remains intact”
What enzyme is deficient in Pompe Disease (type II)?
Lysosomal acid alpha-1,4-glucosidase
How does Pompe disease typically present?
Cardiomegaly
Hypertrophic Cardiomegaly
Hypotonia (low muscle tone)
Exercise Intolerance
Early Death
“Pompe trashes the Pump (heart+muscle)”
What enzyme is deficient in Cori Disease (type III)?
Debranching enzyme
(alpha-1,6-glucosidase)
How does Cori disease typically present?
Milder form of Von Gierke Disease
(with normal blood lactate levels)
Acummulation of Dextrin-like structures in the cytosol
Is gluconeogenesis and glycogenolysis intact or impaired in Cori Disease?
Gluconeogenesis is intact
Glycogenoloysis is impaired
(NOTE: in Von Gierke, the severe form of Cori disease, gluconeogenesis remains intact”)
What enzyme is deficient in McArdle disease (type V)?
Skeletal Muscle Glycogen Phosphorylase
(Myophosphorlyase)
“McArdle - Muscle - Myophosphorylase“
How does McArdle disease typically present?
Muscle cramps
Myoglobinuria (red urine)
Arrythmias (due to electrolyte abnormalities)
“McArdle - Muslce Cramps - Myoglobinuria”
