The reported association between the APC I1307K mutation and colon cancer risk was supported by a correlation in these data between personal or family history of CRC or polyps and a gene mutation.
The I1307K sequence variant was not found in 67 patients with esophageal cancer, 53 patients with gastric carcinoma (13 MSI-H and 44 MSI-negative), or ten patients with sporadic MSI-H colon cancer.
However, a second study indicated that the I1307K mutation did not contribute greatly to the risk of colon cancer in Ashkenazi breast-ovarian cancer families, and a role of mismatch repair deficiency was suggested.
We have shown that the family's phenotype does not result from APC mutations (including the I1307K variant) or from genetic changes in the other known genes that predispose to colon cancer.
Significantly, of the 12 individuals who possessed theI1307K mutation, none was diagnosed with colorectal cancer and none had a known first-, second-, or third-degree relative diagnosed with colon cancer.