Cause — a genetic defect in the lactate dehydogenase enzyme, which affects the processing of carbohydrates

Onset — early adulthood

Symptoms — exercise intolerance, episodes of myoglobinuria (rust-colored urine indicating breakdown of muscle tissue); a skin rash is common

Progression — not progressive

Inheritance — autosomal recessive, or caused by the contribution of a defective gene from each parent

Facts About Metabolic Diseases of Muscle