The Prevalence of Founder Mutations among Individuals from Families with Familial Pancreatic Cancer Syndrome

PURPOSE: Familial pancreatic cancer describes families with at least two first-degree relatives with pancreatic cancer that do not fulfil the criteria of other inherited tumor syndromes with increased risks of pancreatic cancer. Although much has been learned regarding the aggregation of pancreatic cancer in some families, the genetic basis for this familial aggregation is poorly understood. This study evaluated the prevalence of 10 Polish founder mutations in four genes among individuals from families with diagnosed familial pancreatic cancer syndrome and assessed their possible association with the familial pancreatic cancer (FPC) risk in Poland. MATERIALS AND METHODS: In this study, 400 FPC individuals and 4,000 control subjects were genotyped for founder mutations in BRCA1 (5382insC, 4153delA, C61G), CHEK2 (1100delC, IVS2+1G>A, del5395, I157T), NBS1 (657del5), and PALB2 (509_510delGA, 172_175delTTGT) genes. RESULTS: A statistically significant association was observed between the 172_175delTTGT mutation of the PALB2 gene and an increased risk of FPC syndrome (odds ratio [OR], 10.05; p=0.048). In addition, an increased risk of cancer was observed in the FPC family members with a BRCA1 mutation (OR, 6.72; p=0.006). Novel associations were found between the FPC family members with cancer and CHEK2 mutations (OR, 2.26; p=0.008) with a noticeable contribution of the missense variant, I157T of CHEK2 (OR, 2.17; p=0.026). CONCLUSION: The founder mutations in the genes, BRCA1, PALB2, and CHEK2, cause a small percentage of familial pancreatic cancer syndrome in the Polish population. Following confirmation in larger studies, these mutations can be added to the panel of genes to be tested in families with a diagnosis of FPC syndrome.