Boston University researchers have corrected and republished a study that describes a genetic signature of extreme longevity, although the overall findings of associations between genes and longevity are less robust.
The study was retracted from the journal Science last year because of unintentional errors, and after the researchers redid some of the work, the finding did not meet that journal’s standards for publication.
The revised study, published today in the journal PLoS ONE, corrects the problems identified in the original paper. An independent laboratory at Yale University verified that the data were properly analyzed.
In the new study, the researchers identified a single genetic hotspot, which was already known, that had a clear association with exceptional longevity that was not due to chance. The first paper had identified many more genetic hotspots that appeared to be strongly associated with extremely long life.
Instead of associating individual genes with the trait of extremely long life, the researchers repeated their use of novel analysis techniques to identify groups of genes that, together, were predictive of extreme longevity. The results continued to support the idea that genetics plays a larger role in those who live the very longest.
A spokeswoman for Science said in an e-mail that the journal could not reveal details about the journal’s peer review process and why the paper was not accepted after the problems were fixed.
The authors “submitted the corrected data to Science in December 2010, where the work underwent careful peer-review. Although the authors remain confident about their findings, Science has concluded on the basis of peer-review that a paper built on the corrected data would not meet the journal’s standards for genome-wide association studies,” the journal said in a statement at the time of the retraction.
The initial study drew criticism because different technologies were used to analyze the genes of a large sample of centenarians, introducing errors.
In a statement on its blog, PLoS ONE editors wrote that the study was published after peer review.
“While we recognize that aspects of this study will attract attention owing to the history and the strong claims made in the paper, the handling editor, Greg Gibson, made the decision that publication is warranted, balancing the extensive peer review and the spirit of PLoS ONE to allow important new results and approaches to be available to the scientific community so long as scientific standards have been met,” the editors wrote. “We trust that publication will facilitate full evaluation of the study.”
The new study found it possible to predict with 60 percent to 85 percent accuracy whether a person would be extremely long-lived. The genetic signatures were able to make that prediction within the samples included in the study, but because it is such a rare trait to live to be greater than 100, the actual predictive power of such a test on a normal population would be close to zero.
“We believe the data support this idea that there’s an increasingly strong genetic component to exceptional longevity," said Dr. Thomas Perls, director of the New England Centenarian Study at Boston Medical Center and the senior author.
Interest in the genetics of centenarians is growing. In October, the X Prize Foundation announced a $10 million prize to be awarded the first team to sequence the genetic material of 100 centenarians within 30 days, for less than $1,000 per genome.