Glycogen storage diseases

Manifestations

Appropriate Tests

 

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)

Full blood count, 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.