Scientists Confirm Rare Genetic Mutations that Ramp up Bowel Cancer Risk
30 September 2009 – Scientists at The Institute of Cancer Research (ICR) have found that people who carry rare mutations within both copies of a gene called MUTYH are 28 times more likely to develop bowel cancer compared to the general population.
The researchers looked for two mutations in the MUTYH gene, called Y179C and G396D, in over 9,000 bowel cancer patients and over 5,000 healthy individuals. The MUTYH gene codes for a DNA base excision repair protein which removes mistakes that build up in the DNA sequence.
Twenty seven people who carried biallelic mutations were in the bowel cancer group, accounting for 0.3 per cent of all bowel cancers in this study. These patients developed bowel cancer when they were relatively young - in their 50s compared with over 80 per cent that occur in people aged 60 and over.
Study author Steven Lubbe, a PhD student at the ICR said: “Although mutations in this gene are very rare and it will only be relevant to a very small percentage of the overall cases of bowel cancer, the results here could be used to detect those people with some of the highest risks and help target screening to relatives of known carriers.”
The researchers also combined their data with previous studies – examining more than 30,000 genetic samples in total – to confirm earlier findings that carriers of mutations in only one copy of their gene have no significant increase in risk for bowel cancer compared to that of the general population.
