Question

Why does von Gierke’s glycogen storage disease (Box 16-2) cause symptoms of gout?

Short answer

Defective gluconeogenesis leads to high lactate levels, which results in the accumulation of uric acid.

Step-by-step solution

Describe Gout.

Goutis a condition associated withincreased amounts of uric acidin the blood. Glucose-6-phosphatase causesGierke's glycogen storage disorder, which results in poor gluconeogenesis.

Role of gluconeogenesis.

Theconversion of lactic acidproduced by muscles to pyruvate and ultimately glucose is one of the functions of gluconeogenesis in the liver. In Gierke's illness, however, gluconeogenesis is inhibited, resulting in a build-up of lactate in the blood.

Role of lactate.

Lactate is excreted in thebloodstream in the same way as uric acid is. As a result, large amounts of lactate compete with uric acid for the same tubular mechanism in the kidney,reducing uric acid absorption.

Cause of Symptom.

As uric acid cannot be eliminated at a regular rate by the kidneys, it builds up in the blood, causing the very same symptom as Gout illness.

Becausedefective gluconeogenesisleads to high lactate levels, which results in the accumulation of uric acid, Gierke's glycogen storage disorder has gout-like symptoms.