Six patients (4.6 percent) had a deleterious sequence variation in MUTYH (five monoallelic and one biallelic). Four patients (3.1 percent) had Lynch syndrome and had a sequence variation in the MLH1 gene; three were aged 50 years or older at AC diagnosis. Deleterious sequence variations in other cancer predisposition genes (APC, CHEK2, SMAD4, and TP53) were seen for five patients (3.8 percent).