CDH1 mutation screen in a BRCA1/2-negative familial breast-/ovarian cancer cohort

Purpose Mutations in the CDH1 gene are linked both to diffuse gastric cancer and invasive lobular carcinoma (ILC). A high mutation rate is found in families fulfilling the diagnostic criteria for hereditary diffuse gastric cancer. Aim of this study was to clarify whether or not there is a significant contribution of CDH1 mutations in hereditary breast-/ovarian cancer (HBOC). Methods Ninety-seven unrelated probands fulfilling the diagnostic criteria for HBOC (96 affected, 1 unaffected) but tested negative for pathogenic BRCA1/2 mutations were screened for CDH1 mutations by denaturing high performance liquid chromatography (DHPLC) and subsequent Sanger sequencing of suspicious and positive DHPLC results. Results In total, we found two potentially pathogenic CDH1 alterations, c.1774G > A, pAla592Thr, and c.2512 A > G, p.Ser838Gly, classified as variants of unknown significance according to ClinVar. In addition, we detected a high number of known CDH1 polymorphisms (n = 62), some of them more frequent in patients with lobular (55%) than in those with invasive ductal carcinoma (27%). Conclusion Although none of the probands studied carried a clearly pathogenic CDH1 mutation, CDH1 could be considered a potential breast cancer gene, esp. for ILC worth including it in the NGS (next generation sequencing) HBOC panel.