Glucagon may be ineffective to treat hypoglycaemia as glycogen cannot be mobilised
- They can be split into those affecting primarily muscle and those affecting the liver.
- See Von Gierke Disease entry
- Glycogen is a high molecular weight polymer of glucose residues. Both liver and muscle contain significant stores of glycogen.
- Glycogen is formed by glycogen synthase and broken down by glycogen phosphorylase.
- They are nearly all autosomal recessive with deficiencies in enzymes important for glycogen storage or breakdown.
- Glycogen is stored in the liver so Hepatomegaly is common but NO SPLENOMEGALY
- Hypoglycaemia is seen - drowsiness, seizures etc..
- Failure to thrive and lactic acidosis and hypoglycaemia
- Most present in infancy to the paediatrician
- older children present with Hypotonia, muscle weakness and wasting
Complications long term
- Severe hypoglycaemia, cerebral oedema, coma and even death
- Hepatic tumours - adenoma and adenocarcinoma
- Glomerular hyperfiltration and glomerulosclerosis
- Brain damage, Severe anaemia
- Failure to thrive and Growth failure
- 1 - von Gierke's (glucose-6-phosphatase deficiency)- Hepatomegaly, hypoglycaemia and lactic acidosis. High mortality though some survive.
- 2 - Pompe's disease - Heart failure and hypotonia. Death in infancy
- 5 - McArdle's disease - Muscle cramps, proximal wasting. Normal life expectancy.