hepatoencephalopathy due to combined oxidative phosphorylation defect type 1 (Monarch Disease Ontology entry MONDO_0012191) can be described as follows. Hepatoencephalopathy due to combined oxidative phosphorylation deficiency type 1 is a rare, inherited mitochondrial disorder due to a defect in mitochondrial protein synthesis characterized by intrauterine growth retardation, metabolic decompensation with recurrent vomiting, persistent severe lactic acidosis, encephalopathy, seizures, failure to thrive, severe global developmental delay, poor eye contact, severe muscular hypotonia or axial hypotonia with limb hypertonia, hepatomegaly and/or liver dysfunction and/or liver failure, leading to fatal outcome in severe cases. Neuroimaging abnormalities may include corpus callosum thinning, leukodystrophy, delayed myelination and basal ganglia involvement. Also known as: GFM1 combined oxidative phosphorylation deficiency, Hepatoencephalopathy due to COXPD1, combined oxidative phosphorylation deficiency caused by mutation in GFM1, combined oxidative phosphorylation deficiency type 1.