APC and Peutz-Jeghers syndrome: Furthermore, familial pancreatitis is associated with a mutation in the PRSS1 gene, hereditary nonpolyposis-related colorectal cancer (HNPCC/Lynch syndrome) most often caused by a defect in the MLH1 or MSH2 gene, Peutz-Jeghers syndrome (PJS) is caused by defects in the STK11 gene and FAP syndrome is caused by a germline mutation in the APC gene [21,22,23,24,25].