The KRAS c.34G>T mutation had a positive predictive value of 75 % and a negative predictive value of 89.3 % in adenomas compared with a positive predictive value of 100 % and negative predictive value of 86.7 % in CRCs, indicating that the somatic KRAS mutation may not be as clinically useful in identifying biallelic MUTYH cases in adenomas as it is in CRCs. This evidence concerns the gene KRAS and adenoma.