The chance of developing genetic mutations in blood cells that can lead to leukaemia increases as a person gets older, a study published in Cell Reports has found.
The study, performed by researchers at the Wellcome Trust Sanger Institute, used a technique called 'ultra-deep sequencing' to analyse blood samples from 4129 people without health conditions. The study found that 20 per cent of people aged between 50 and 60 had genetic defects associated with developing leukaemia. The proportion rose in line with age, with 70 per cent of people over the age of 90 possessing the defects. This will help in understanding elderly health.
Dr George Vassiliou, one of the study's authors, said: 'These mutations will be harmless for the majority of people but for a few unlucky carriers they will take the body on a journey towards leukaemia. We had suspected people had these mutations, but didn't expect they would be an almost inevitable consequence of ageing.'
However, the study noted that despite the large number of genetic defects identified in older people, a mutation in a gene called NPM1, which is a key trigger of leukaemia, was not found in any of the participants. The study's authors suggested that there was a need for an additional genetic trigger for the disease.
Dr Thomas McKerrell, an author of the study, said: 'Leukaemia results from the gradual accumulation of DNA mutations in blood stem cells, in a process that can take decades. Over time, the probability of these cells acquiring mutations rises. What surprised us was that we found these mutations in such a large proportion of elderly people. This study helps us understand how ageing can lead to leukaemia, even though the great majority of people will not live long enough to accumulate all the mutations required to develop the disease.'