Several studies have investigated the role of mtDNA variants in the development and progression of complications associated with diabetes mellitus (DM) specially causing microvascular and macrovascular complications viz., mtDNA 3243 A > G Variant (MT-TL1 Gene), mtDNA 8993 T > G Variant (ATP6 Gene), mtDNA 13513G > A Variant (ND5 Gene), mtDNA Deletions and mtDNA haplotypes. The gene discussed is MT-ATP6; the disease is diabetes mellitus.