Some variants of mitochondrial DNA are well correlated with longevity; numerous studies have identified SNPs and haplotypes found far more often in long-lived people. This shouldn't be surprising, given the evidence indicating an important role for mitochondria in determining life span. Here is a Chinese study to add to the others: "OBJECTIVE: To investigate the human mitochondrial DNA (mtDNA) variations associated with longevity in Bama elderly population from Guangxi. METHODS: Mitochondrial genome of 20 individuals over 96 years of age was sequenced, and seven target single nucleotide polymorphism(SNPs) were observed by comparing with the standard rCRS sequence, and two were tested by polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP) method in a larger population including 208 individuals of 90-113 years old, and 586 unrelated control individuals from Guangxi. RESULTS: The 4824G frequency of the mtDNA4824A/G locus increased with age both in the long-lived elderly and in controls. And it was significantly higher in controls than that in long-lived population. CONCLUSION: The mtDNA4824 A/G is not only an age-related locus, its mutation is also negatively correlated with longevity."

Link: http://www.ncbi.nlm.nih.gov/pubmed/20677150