Hereditary diffuse gastric cancer (HDGC) is an inherited genetic syndrome most often caused by an inactivating mutation in the E-cadherin gene (CDH1) located on chromosome 16. Individuals who inherit an inactive copy of the CDH1 gene are at significantly elevated risk for developing stomach cancer. For this reason, individuals with these mutations will often elect to under go prophylactic gastrectomy, or a complete removal of the stomach to prevent this cancer. Mutations in CDH1 are also associated with high risk of lobular breast cancers, and may be associated with a mildly elevated risk of colon cancer.