Given the increasing influence of targeted exome capture and next generation sequencing to identify novel genes associated with early-onset mitochondrial disease, including several mt-aminoacyl-tRNA synthetases such as AARS2[14] and EARS2[15], our study nicely demonstrates that routine diagnostic genetic testing methodologies including array CGH can be crucial in the identification of underlying genetic defects. This evidence concerns the gene AARS2 and inborn mitochondrial metabolism disorder.