Severe lactic acidosis. Death is typical within the first year. Progressive external ophthalmoplegia, limb weakness, peripheral neuropathy, digestive tract disorders, leukodystrophy, lactic acidosis, ragged red fibers. Leigh Syndrome may result if the percentage of mutation is high enough. Single mitochondrial DNA deletions.
Inheritance is usually sporadic.
Those who survive infancy usually develop Kearns-Sayre Syndrome . See the discussion about the Pearson Marrow - Pancreas Syndrome International Survey . Lactic acidosis, hypoglycemia, severe retardation, failure to thrive. Lactic acidosis, ataxia, pyruvic acidosis, spinal and cerebellar degeneration. Sometimes found to be the cause of Leigh Syndrome .