Glycogen storage diseases Flashcards
Defects in what
Defects in the enzymes of synthesis or degradation of glycogen
Type 0 defects with what enzyme
Glycogen synthase
Type I defects with what enzyme
G-6-Pase
Type II defects with what enzyme
Debranching enzyme
Type III defects with what enzyme
Branching enzyme
Type IV defects with what enzyme
Glycogen phosphorylase
Type I affects what organs and what happens
Liver and kidneys
G-6-Pase - creates free glucose - impaired export of glucose from liver = hypoglycaemia
High G-6-P in liver
von Gierke’s disease
Type II causes death how?
No alpha 1,4 glucosidase
Cardiorespiratory failure
Pompe’s disease
Type III what does it cause
No debranching enzyme
Hypoglycaemia
Cori’s disease
Type IV pathophysiology
Long unbranched chains that have low solubility
Andersen’s disease
Type V problems
Affects muscle glycogen phosphorylase - muscle can’t break down glycogen
Low exercise tolerance
McArdles disease
High levels of G-6-P in liver and kidney results in
Metabolised to lactic acid or it is converted to glycogen or lipid (increased glycolysis = lactic acidosis); increased fatty acid, TG and VLDL synthesis; enlargement of liver/kidneys
How to treat/manage
Correct hypoglycaemia and keep blood glucose at normal levels
Glucose drinks, nasogastric tubes, uncooked cornstarch
Restrict dietary lipids
Liver transplant
