Glycogen Storage Disorders Flashcards
What are the names of the glycogen storage disorders Type I - VII?
I. von Gierke, II. Pompe, III. Cori, IV. Andersen, V. McArdle, VI. Hers, VII. Tarui
What is the enzyme deficiency in von Gierke disease?
glucose 6 phosphatase
What is the enzyme deficiency in Pompe disease?
lysosomal alpha-1,4-glucosidase, aka acid maltase
What is the enzyme deficiency in Cori’s disease?
alpha-1,6-glucosidase (aka debranching enzyme)
What is the enzyme deficiency in Andersen’s disease?
amylo-1,4-1,6-transglucosidase (branching enzyme)
What is the enzyme deficiency in McArdle’s disease?
skeletal muscle glycogen phosphorylase
What is the enzyme deficiency in Hers’ disease?
hepatic glycogen phosphorylase
What is the enzyme deficiency in Tarui’s disease?
Muscle isoform of phosphofructokinase
What is the presentation of von Gierke’s?
Severe fasting hypoglycemia, elevated lactate, uric acid, and triglycerides, hepatorenomegaly
What is the presentation of Pompe’s disease?
Left ventricular hypertrophy, with no hypoglycemia - liver, heart, and muscle are affected most.
What is the presentation of Andersen’s?
Usually fatal. Infantile cirrhosis, failure to thrive, hypotonia. Hepatosplenomegaly
Which GSDs present with milder symptoms?
McArdle (V) and Tarui (VII) both present with exercise intolerance. Hers’ presents in childhood but symptoms improve with age.
Which have irregular glycogen?
Cori (short branches - “dextrin-like”) and Andersen (not branched)
What disaccharides should patients with von Gierke’s disease avoid?
Fructose and galactose
Does Pompe cause hypoglycemia?
No, bc lysosomal alpha-1,4-glucosidase only does about 3% of glycogenolysis.
