In a study of 81 Japanese FPC patients, possibly deleterious germline variants were detected in 18 (22.2% of cases): ATM: 7; BRCA2: 3; ASXL1: 2; DNMT3A: 2; ERCC4: 2; and MLH1: 2 [121]. Here, BRCA2 is linked to Familial adenomatous polyposis.