CDKN2A and Lynch syndrome: a) 37 Lynch syndrome (MLH1, MLH2, MSH6, PMS2)b) 1 APC c.3920T>A, p.l1307K & PMS2c) 9 double somatic MMR mutationsd) 1 somatic MLH1 methylation402 (89.3%) had MMR-proficient tumors and 32 (8%) had at least 1 gene mutation:a) 9 high-penetrance CRC genes (APC, APC/PMS2, MUTYH, SMAD4)b) 13 high-penetrance other cancer-associated genes (ATM, BRCA1, BRCA2, CDKN2A, PALB2)c) 10 low-penetrance CRC genes (APC c.3920T>A, p.l1307K, monoallelic MUTYH)