Complex V deficiencies present with lactic acidosis, and an elecated lactate/pyruvate ratio. Most patients present with neonatal-onset hypotonia, hyperammonemia, hypertrophic cardiomyopathy, and 3-methylglutaconic aciduria.
A. Multisystemic forms
1. Leigh syndrome
2. NARP (Neuropathy, ataxia, retinitis pigmentosa)
3. Familial bilateral striatal necrosis
4. Fatal infantile multisystemic disease
On imaging patients have cortical-subcortical atrophy, dysgenesis of the corpus callosum with absent anterior genu and rostrum, and hypoplasia of whie matter