| A rare mitochondrial oxidative phosphorylation disorder with characteristics of a spectrum of three main clinical phenotypes comprising a severe neonatal phenotype with early fatal lactic acidosis, a more protracted course with early-onset developmental delay, motor weakness, extrapyramidal signs with or without epilepsy and a phenotype with normal early development and Parkinson-like symptoms starting around the age of one year. Additional variably reported signs and symptoms include cardiomyopathy, optic anomalies, hepatosplenomegaly and abnormal brain MRI findings among others. Deficiencies in mitochondrial oxidative phosphorylation enzymes are inconsistent. |
