Definition - one of a group of muscle diseases that interfere with the processing of carbohydrates for energy production

Cause - a genetic defect in the phosphofructokinase enzyme, which affects the breakdown of glucose

Onset - - teens to 30s

Symptoms - exercise intolerance, with pain and cramps, made worse by high-carbohydrate meal; myoglobinuria (rust-colored urine indicating breakdown of muscle tissue) after vigorous exercise

Progression - not progressive, although weakness between episodes of exercise intolerance may occur late in disease

Inheritance - autosomal recessive, meaning caused by the contribution of a defective gene from each parent

Facts About Metabolic Diseases