Von Gierke's

Question 1

Von gierke’s

Answer 1

represents the largest group of glycogen storage disorders
enzyme defect in glucose-6-phosphatase so that G-6P cannot be converted into free glucose, but is instead metabolised into lactic acid or incorporated into glycogen

Question 2

effects

Answer 2

liver and kidney involvement
hypoglycaemia is a major feature
large quantities of glycogen is formed and stored in the hepatocytes, renal and intestinal mucosa cells, leading to hepatomegaly and renal enlargement
abnormalities of lipids may lead to xanthoma formation
uric acid often elevated and can lead to gout
galactose, fructose and glycerol are all metabolised to lactate, causing a metabolic acidosis

Question 3

presentation

Answer 3

shortly after birth, hypos and lactic acidosis can lead to convulsions
more moderate hypos can lead to irritability, pallor cyanosis, hypotonia, tremors, LOC and apnoea
some children have diarrhoea due to pseudo-colitis
characteristic rounded doll’d face due to deposition of fat
hepatomegaly can cause visible abdo distension
growth restricted, height usually below the 3rd centile
puberty delayed
mental development normal
mouth ulcers
skin and mucous membranes may show eruptive xanthomas or gouty tophi on the extensor surfaces of extremities
uric acid arthropathy may develop
altered platelet function can cause bleeding, especially epistaxis, and may result in iron deficiency anaemia
in subtype Ib there are also immune disturbances, so there can be significant mortality

Question 4

investigations

Answer 4

blood glucose and pH are usually low with elevated lactate, uric acid, triglyceride and cholesterol
urea and creatinine may be raised if renal function is impaired
anaemia
neutropenia in type Ib as a result of freq bacterial infections
lactic acidosis
in older patients, anaemia, neutropenia and proteinuria (or at least microalbuminuria) may show

Question 5

special tests

Answer 5

USS to assess and monitor size of liver and kidneys and to detect possible hepatic adenomas and nephrocalcinosis
glucagon does not cause a rise in glucose levels, but it does raise lactic acid levels
oral galactose and fructose fall to increase glucose levels, but plasma lactic acid levels increase
glucose tolerance test progressively lowers lactic acid over several hours
bone density test is highly recommended as soon as possible in childhood