Regarding new variants affecting MT-ATP6, MT-ATP8, or both, m.8561C>T, which causes a defect in CV assembly, was reported in a child with early onset ataxia, psychomotor delay, and microcephaly [42], whereas functional studies have been performed for the m.8382C>T, m.8424T>C, m.8806C >G, m.8975T>C, m.9008C>G, and m.9019A>G variants [34]. This evidence concerns the gene MT-ATP6 and cerebellar ataxia.