First gene variant linked to ageing identified
8 February 2010
The variants, located near a gene called TERC, were discovered by researchers from the University of Leicester, King's College London and the University of Groningen in the Netherlands, who analysed over 500 000 genetic variants in the genomes of around 13 000 people.
There are two forms of ageing: chronological ageing (age in years) and biological ageing, where the cells of some individuals are older, or younger, than suggested by their actual age. There is accumulating evidence that the risk of age-associated diseases, including heart disease and some types of cancers, are more closely related to biological rather than chronological age.
The researchers studied structures on the ends of chromosomes called telomeres, used as a marker for biological ageing. Individuals are born with telomeres of certain length and in many cells telomeres shorten as the cells divide and age.
"We found that those individuals carrying a particular genetic variant had shorter telomeres i.e. looked biologically older," said Professor Nilesh Samani, British Heart Foundation Professor of Cardiology at the University of Leicester, who co-led the project.
"Given the association of shorter telomeres with age-associated diseases, the finding raises the question whether individuals carrying the variant are at greater risk of developing such diseases."
"TERC is already known to play an important role in maintaining telomere length," said Professor Tim Spector from King's College London, who co-led the project.
"What our study suggests is that some people are genetically programmed to age at a faster rate. The effect was quite considerable in those with the variant, equivalent to between 3-4 years of 'biological ageing' as measured by telomere length loss."
"Alternatively, genetically susceptible people may age even faster when exposed to proven 'bad' environments for telomeres - like smoking, obesity or lack of exercise - and end up several years biologically older or succumbing to more age-related diseases."
The study was funded by the British Heart Foundation and the Wellcome Trust.
Image: Portrait of an older lady in black and white. Credit: loungerie on Flickr
Codd V et al. Common variants near TERC are associated with mean telomere length. Nat Genet, 2010 [Epub ahead of print].