Additionally, testing for the CDH1 mutation is supported in families with bilateral or multiple cases of lobular breast cancer before the age of 50 years, families with a clustering of DGC and cleft lip/cleft palate, or any patient diagnosed with gastric in situ signet-ring cells and/or pagetoid spread of signet-ring cells [6,7]. This evidence concerns the gene CDH1 and Hereditary breast cancer.