Genetic variant may pinpoint those at risk of age-related diseases
Scientists have pinpointed the genetic variants that may explain why some people age earlier than others ? and say the findings could help spot people at higher risk of age-related illnesses.
Dutch and British researchers analysed more than 500,000 genetic variations from human gene maps and found that people with particular variants near a gene called TERC were likely to be biologically older by three to four years.
"What our study suggests is that some people are genetically programed to age at a faster rate. The effect was quite considerable in those with the variant," said Tim Spector from King?s College London, who co-led the study.
In a study published in the Nature Genetics journal, the scientists explained that there are two forms of aging -- chronological aging, counted in years, and biological aging, in which the cells of some people are older, or younger, than their chronological 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," said Nilesh Samani, a cardiology professor at Britain?s Leicester University, who worked on the study.
People carrying the variant had differences in the "biological clock" within all their cells. One theory suggests that biological timers called "telomeres", part of the chromosomes in every cell that carry genetic code, may be a factor in this.
From birth, every time a cell divides, the telomeres get shorter and there is some evidence that people with shorter telomeres, either because they diminish more quickly or because they were born with shorter versions, may be at higher risk from age-related illness.
The scientists have discovered that a variant of gene called TERC determines not only how long the telomeres are when someone is born, but also how quickly they shorten.
Prof Samani said: "In this study what we found was that those individuals carrying a particular genetic variant had shorter telomeres, i.e. looked biologically older.
"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."
Added the 09 February 2010 in category Innovation News