A genetic test which tells whether you will make it to your century has been developed by scientists.
The computer program will give individuals their odds of reaching the age of 100 – and tell them whether their chances are higher or lower than average. Its inventors, from the respected Boston University in the U.S., say it will allow those not blessed with the cocktail of ‘centenarian genes’ to make changes to their lifestyle to maximise the time they have.
But the breakthrough raises moral questions about the effects of being told your destiny – and about who picks up the pieces if the test results are wrong.
There is also the fear that insurance and pension firms could use the information to alter premiums and payouts. The researchers studied the DNA of 1,600 centenarians, including some as old as 119, and compared it with the DNA of others.
This highlighted 150 genetic changes which were more common in those who lived to a ripe old age. They could be broken down into 19 groups, or genetic ‘signatures’, the journal Science reports.
Researcher Dr Paola Sebastiani said: ‘Some signatures correlate with the longest survival, other signatures correlate with the most delayed onset of age-related diseases such as dementia or cardiovascular disease.’ Understanding how these genes lengthen life or protect against illness could lead to new drugs to fight disease.
The researchers are now completing work on a computer program which can tell whether someone is predisposed to a long life – as long as they have information on their genetic code to hand. It could be available to other scientists within days, before being released to the public. The researchers are not patenting the information, meaning there is nothing to stop a biotech company creating an easy-to-use commercial kit.
But there are concerns about the reactions of those given the news that their life could be longer or shorter than they’d expected. And the researchers’ method is only 77 per cent accurate – meaning almost a quarter of those tested could be told they didn’t have what it takes to live to 100, when in fact they did.
One in 15 has the right combination of genes to live to 100, but just one in 600 actually makes it, meaning factors such as healthcare, diet and exercise are hugely important. Dr Muireann Quigley, a Manchester University bioethicist, warned: ‘Having these genes doesn’t mean you are invulnerable to having an accident or getting knocked down.’
The above was publishedthis was published online 21 July 2011:
A prominent paper that claimed to reveal the genetic factors that help people live to 100 or older has been retracted1, a year after it was first released.
The study, published in Science2, reported 150 genetic variations that could be used to predict whether a person was genetically inclined to see their 100th birthday. The results were based on a search through the genomes of more than 1,000 centenarians.
But shortly after the paper was published, a host of criticisms arose. In particular, geneticists noted that the control samples and the samples from centenarians were analysed in slightly different ways. Last November, Science editor Bruce Alberts published an editorial expression of concern3 and noted that the authors were working to address the issue.
Today, the authors are officially retracting the paper, acknowledging that the original analysis was flawed. The team, led by Paola Sebastiani, a biostatistician at Boston University School of Public Health in Massachusetts, and Thomas Perls, a gerontologist at Boston University School of Medicine, collaborated with an outside laboratory to identify and remove affected data, and used a different genotyping platform to confirm their results. Ultimately, the reanalysis yielded a new set of genetic variations that might contribute to extreme longevity.
“However,” the authors wrote in their retraction, “the specific details of the new analysis change substantially from those originally published online to the point of becoming a new report. Therefore, we retract the original manuscript and will pursue alternative publication of the new findings.”
The incident could haunt the work of others who are searching for the genetic underpinnings of longevity, says Thomas Kirkwood, director of the Institute for Ageing and Health at Newcastle University, UK. “It means that people are going to be more cautious about future studies,” he says.
A retraction like this is evidence that wrong things published in scientific journals do get caught even if they pass initial review. The system works, eventually. Can a genetic test tell your odds of living to 100? It depends on how big a role genetics play. If only 1/4 of the variance in human lifespan is due to genetics, it is best to focus on lifestyle.
Subsequent studies, however, show that this genetic impact did not appear to extend to longevity. Sure, strongly genetic traits such as heart disease and diabetes can affect lifespan, but the data revealed that identical twins still tended to die years apart, only slightly closer together than fraternal twins. Overall, subsequent research has found that genetic differences probably account for only about a quarter of the variance in adult human lifespan.So, we are primarily left with nurture and lifestyle as the defining forces determining our life span. This may be bad news if you had a grandparent who lived to 100 and thought you could eat steak and drink bourbon every day. It is probably good news, however, for the rest of us, because it means the die is not cast.