Pyruvate Metabolism Disorders

Description

Pyruvate is formed in the processing of carbohydrates (source of sugar for the body), fats, and proteins, and is an energy source for the mitochondria, the energy-generating components of a cell.
Hereditary problems with pyruvate metabolism can disturb the functioning of the mitochondria, causing any of a variety of symptoms, such as muscle damage, mental retardation, seizures, a build-up of lactic acid leading to excess acid in the body ( acidosis ), or failure of organ function, including that of the heart, lungs, kidneys, or liver. Such problems may develop any time between early infancy and late adulthood. Exercise, infections, or alcohol consumption can worsen symptoms, leading to severe lactic acidosis with muscle cramping and weakness.

Two autosomal recessive pyruvate metabolism disorders are:

1. Pyruvate dehydrogenase complex deficiency. Can cause the accumulation of pyruvate in the blood. As a result, the level of lactic acid in the blood rises, causing acidosis. Can also cause abnormalities of the central nervous system, seizures and retardation. This disorder cannot be cured, but some are helped by a diet high in fat.
2. Pyruvate carboxylase deficiency. Like pyruvate dehydrogenase complex deficiency, interferes with or blocks the production of glucose in the body and thus can cause the accumulation of pyruvate in the blood and thus acidosis. Can also cause abnormalities of the central nervous system and retardation as well as hypoglycaemia (low blood sugar levels) because glucose is not synthesised. Hypoglycaemia and acidosis may be relieved by eating frequent carbohydrate-rich meals, however there is no treatment for the neurological symptoms. Often this disease is fatal.

The information in this page is presented in summarised form and has been taken from the following source(s):
1. The Encycloædia Britannica© Online: http://www.britannica.com/