A study of over 1000 centenarians published in the prestigious science journal Science has identified 150 gene variants associated with extreme longevity, which has been defined as a lifespan of over a 100 years.

Researchers found, while most super-centenarians carried all the longevity markers, centenarians had various genetic variants combinations categorized in 19 genetic profiles.

While, centenarians were not found to be free of genetic variants associated with diseases, the fact remains that they remain unaffected by diseases partly due to the longevity SNPs that negate the negative effect of disease gene variants.

The study involving 1,055 centenarians and 1,267 younger people, initially only identified 33 SNPs, however, the researchers believe there are more and they may be able to discover 150 SNPs associated with extreme longevity.

The researchers setting up a statistical model based on the 150 SNP variants, found 77% of the time they were able to successfully predict who was a centenarian. However, this genetic model did not predict who would or would not amongst the general population live over 100 years.

Nicholas Schork, a statistical geneticist at the Scripps Translational Science Institute and the Scripps Research Institute has been cited as saying these gene variants are just markers and not meant to predict a person's longevity in a general population.

Essentially, this means it is unknown whether these gene variants play any major role in the retarded aging process, despite some genes that have been found to be associated with certain diseases like Alzheimer's, chromosome stability and insulin amongst others.

The scientists are still at sea why the model based on these newly located genetic variants cannot accurately identify all the centenarians, leading them to believe there are other rare genetic variants or lifestyle remaining unknown, or a genetics and lifestyle parameter combination responsible for their longevity.

According to the ScienceNews report, overall genetics only account for 20 to 30% of a person's chances of living beyond 85 years, with environmental factors like diet and healthy lifestyle playing a major role in a person's longevity.