Carnitine-acylcarnitine translocase (CACT) deficiency is a life-threatening, inherited disorder of fatty acid oxidation which usually presents in the neonatal period with severe hypoketotic hypoglycemia, hyperammonemia, cardiomyopathy and/or arrhythmia, hepatic dysfunction, skeletal muscle weakness, and encephalopathy. The disease is carnitine-acylcarnitine translocase deficiency (Monarch Disease Ontology identifier MONDO_0008918). Also known as: CACT deficiency.