In addition, different amino acid substitutions in MT-ATP6 are responsible for human pathologies such as NARP/MILS, LHON or Leigh diseases (Figure 1E) among others, several of them being located adjacent or very close to the equivalent of mouse 163 position mutated in the clone BcTMPII.1 and affecting aH5 helix. This evidence concerns the gene MCAT and Leber hereditary optic neuropathy.