The causes of hereditary susceptibility to some women cancers have been documented to include hereditary cancer susceptibility genes, BRCA1 or BRCA2, associated with HBOC syndrome [22, 23], DNA mismatch repair genes, MLH1, MSH2, MSH6, or PMS2, in Lynch/Hereditary Non-Polyposis Colorectal Cancer in endometrial, colorectal and OC [24, 25], Cowden syndrome in endometrial and BC [26, 27] and Li-Fraumeni syndrome in BC [28, 29]. The gene discussed is PMS2; the disease is Cowden disease.