The factors that contribute to a long life have been extensively studied. After studying many individuals that are 100+ years old, a small set of genetic variation was found. There is no single gene that allows people to live to 100 and beyond, but there is a combination of genes found in people that live much beyond the normal life expectancy.
“These markers may have some predictive power down the road for people who want to know if they’re destined for long life, researchers said. But genes alone are far from the whole story: For the vast majority of people, environment and lifestyle are also known to play important roles in aging.”
Prior to this study, it was thought that thousands of genes predicted one’s longevity. This research has narrowed down the gap to about 150 markers. The study suggests that these genes are able to counter many of the negative effects that are normally caused diseased genes.
http://www.latimes.com/news/science/la-sci-longevity-genes-20100702,0,1192424.story