Two more patients (one male at the age of 26 with FAP and sigmoid colon cancer and one male at the age of 46 with ascending colon cancer and rectum cancer) had one novel frameshift variant each (FANCI c.3340delA and BMPR1A c.152delC, respectively) in combination with other previously reported frameshift variants (APC c.3613delA and CHEK2 c.599T > C, respectively, Table 3). Here, CHEK2 is linked to Familial adenomatous polyposis.