Most commonly the disorder affects the heart
(progressive cardiomyopathy with cardiomegaly), but it also affects the
central nervous system (encephalopathy with lethargy, somnolence, coma,
sensorimotor neuropathy, muscle weakness and hypotonia) and the eyes
(pigmented retinopathy). Other features may include hepatomegaly, abdominal
pain, vomiting and diarrhea. Laboratory findings may include hypoglycemia,
decreased levels of carnitine in plasma, liver, and muscle, high fasting
plasma fatty acids, hyperammonemia, and absence of ketonuria. A complete
blood count may reveal a hypochromic, microcytic anemia.