Glycogen Storage Diseases

Glucose-6-phosphatase (Glucose 6-P --> Glucose)

Severe hypoglycemia, lactic acidosis, hepatomegaly, hyperlipidemia, hyperuricemia, short stature

Normal Glycogen structure, just trapped in the liver

Giving Galactose or Fructose cause no increase in blood glucose, nor does administration of glucagon or EPI

Lysosomal Alpha-1,4-glucosidase deficiency (normally digests glycogen-like material in endosomes)

DEATH by 2 years, cardiomegaly (usual COD), muscle weakness

Glycogen-like material in inclusion bodies that should have been degraded in tissues that normally have glycogen stores

Glycogen debranching enzyme deficiency

Mild hypoglycemia, liver enlargement

Short outer branches, Single glucose residue at outer branch

Branching enzyme deficiency

DEATH by 2 yo, infantile hypotornia, cirrhosis

Very few branches, especially toward periphery

Muscle glycogen phosphorylase deficiency (Glycogen --> Glucose 1-P)

Muscel cramps and weakness on exercise

Normal Glycogen structure

Hepatic glycogen phosphorylase (Glycogen --> Glucose 1-P)

Mild fasting hypoglycemia, hepatomegaly, cirrhosis

Normal Glycogen structure

Gluconeogenesis compensates, hepatomagaly and growth retardation may be present in early childhood, although hepatomegaly may improve with age