Glycogen storage disease Flashcards
Glycogen storage disease
Defects in enzymes of synthesis or degradation of glycogen
10 types
All autosomal recessive except IX is sex linked
Type 0
Glycogen synthase affected
Type I
G-6-Pase affected
Type II
alpha- 1,4 glucosidase affecting
Type III
Amylo 1,6 glucosidase affected
debranching enzyme
Type IV
Branching enzyme affected
Type V
Glycogen phosphorylase affected
Von Gierke’s disease
Type I
Deficiency in G6Pase
Excess G-6-P so excess storage of glycogen and liver enlargement
Stunted growth, hypoglycaemia, hyperlactaemia, hyperlipidaemia
Hyperuricaemia, neutropeania
Pompe’s disease
Type II
Deficiency in alpha- 1,4 glucosidase in the lysosome
Death by cardiorespiratory failure
Cori’s disease
Type III
Deficiency in amylo- 1,6 glucosidase
Unable to break down glycogen
Symptoms disappear at puberty
Anderson’s disease
Type IV
Long unbranched chains that have low solubility
Rarely live beyond 4 years
McArdle’s syndrome
Affects muscle glycogen phosphorylase
Muscle cannot break down glycogen
Low tolerance to exercise and fatigue easily
Painful muscle cramps after exercise
Normal life span
