Glycogen storage diseases
Last updated: Friday, 06, August, 2010
Consult pathologist prior to investigation.
If liver biopsy indicated: histology, glycogen assay, and appropriate specific enzyme assays (unfixed specimens must be submitted immediately to laboratory).
Asymptomatic hepatomegaly (type VI, type IX)
Liver biopsy - glycogen phosphorylase (type VI), phosphorylase kinase (type IX).
Hepatomegaly with hypoglycaemia (type I, type III)
FBC, blood film.
Liver biopsy - glucose-6-phosphatase (type I), debrancher enzyme (type III).
Muscle pain, cramps, myoglobinuria, myopathy (McArdle's - type V, type VII)
Ischaemic exercise test; muscle biopsy - phosphorylase (type V), phosphofructokinase (type VII).
Cardiac failure in infancy (Pompe - type II)
Muscle biopsy, fibroblast culture or lymphocytes - acid alpha glucosidase.
Cirrhosis (type IV)
Liver biopsy - brancher enzyme.