APC I1307K and E1317Q variants are rare or do not occur in Swedish colorectal cancer patients.

Recently, a germ line mutation of the APC gene, I1307K, was discovered in a subset of Ashkenazi jews. The mutation involves an amino acid exchange and creates a tract consisting of eight contiguous adenosine residues believed to cause hypermutability in this region. Another germ line missense variant, E1317Q, not restricted to a certain ethnic population, could functionally alter the protein. These APC variants have been linked with increased colorectal cancer risk in several studies. However, they have not yet been investigated in Swedish colorectal cancer patients. Thus, our aim was to investigate the prevalence of I1307K and E1317Q in Swedish colorectal cancer patients in order to determine if these genetic variants are important predisposing factors to colorectal cancer in this population. To this end, sequence analysis was carried out of the APC gene in order to identify any I1307K and E1317Q variants in 106 unselected cases and 88 hereditary/familial colorectal cancer cases including 22 cases of hereditary non-polyposis colorectal cancer (HNPCC) fulfilling the Amsterdam criteria. Out of a total of 194 cases examined, we did not find any variants. It seems that these alterations are rare or absent in the Swedish population.