A single event can release a chain of hundreds of mutations, and trigger cancers much more quickly than usual, a UK scientist has discovered.
Peter Campbell at the Wellcome Trust Sanger Institute in Cambridge, spotted that a chromosome had apparently been smashed into hundreds of fragments and stuck back together, Humpty Dumpty-like.
The result was a random mosaic of genetic material containing a number of cancer-causing mutations.
"The first patient was a chance finding and we didn't know what to make of it," the New Scientist quoted Campbell as saying.
After sequencing genomes from over 700 people with a range of cancers, Campbell and his team found the same pattern of damage in around 2 to 3 per cent of them.
Such serious damage would result in cell suicide but instead some cells appeared to have stitched the chromosome fragments back together. In some cases there were up to three cancer-causing mutations, suggesting those cells have taken a "significant leap on the road to cancer", said Campbell.
One single event has made these cells take a significant leap on the road to cancer
The team are unsure what causes these chromosomes to become "completely pulverised", but speculate that radiation could be to blame.
The study has been published in journal Cell.