A unique, primary mitochondrial disorder has been identified by investigators at the Armed Forces Institute of Pathology, Washington, DC, and the University of California Center for Health Sciences, Los Angeles.
The disorder was found in a 20-year-old man with a 12-year history of easy fatigability upon exertion.
The symptoms first suggested myasthenia gravis, Maj Harold M. Price, MC, said. The pharmacological tests for myasthenia, however, were normal.
A mild proximal muscle weakness with hyporeflexia and a slightly elevated SGOT were the only significant clinical and laboratory abnormalities.
Muscle biopsies taken from the deltoid and gastrocnemius muscles showed essentially normal Type II fibers.
Almost all of the Type I fibers, on the other hand, showed evidence of abnormal lipid deposits associated with what, by light microscope, appeared to be peculiar densities.
The electron microscope showed these densities to be populations of abnormal mitochondria. The structural abnormality was localized to the outer