We report the case of a novel mitochondrial DNA mutation in the MT-ATP8 gene in an infant with tetralogy of Fallot. Next-generation sequencing was applied to sequence whole mitochondrial DNA of the patient. A known Leber's hereditary optic neuropathy-associated mutation (G9804A), a heteroplasmic T7501C mutation (17%), and a novel C8481 T Pro > Leu missense mutation in the MT-ATP8 gene was identified.