Measuring the ends of chromosomes could predict an individual's chance of dying from age-related disorders, such as heart disease.
We already know that in the genetic disorder dyskeratosis congenita abnormal shortening of the chromosome is linked with premature aging. Those with this disease are prone to very early onset of age-related disorders such as heart problems and brittle bones. Analysis shows that the telomeres - the name given to the ends of the chromosomes - shorten very rapidly in this group of people.

But till now no measurements of telomere length have been made among the general population. In a ground-breaking study, researchers at the University of Utah looked at telomere length in 143 people over 60. They found that those with the longest telomeres lived four to five years longer than those with the shortest ones. Shorter telomeres were linked to a threefold increase in the risk of death from heart disease, and an eightfold increase in the risk of death from infection. It looks as if telomere length is a key predictor of survival in humans, as a marker of aging and age-related disease. Maybe the way forward is to intervene with therapies that can preserve telomere length.