Biallelic variants in the <i>CARS2</i> gene (NM_024537.4), which encodes the mitochondrial aminoacyl-tRNA synthetase for cysteine (CARS2, mt-aaRS<sup>cys</sup>; MIM*612800), result in childhood onset epileptic encephalopathy and complex movement disorder with combined oxidative phosphorylation deficiency (MIM#616672). This evidence concerns the gene CARS2 and childhood-onset epilepsy syndrome.