has material basis in germline mutation in CTNNA1 breast lobular carcinoma gastric adenocarcinoma hereditary breast carcinoma hereditary gastric cancer CTNNA1-related diffuse gastric and lobular breast cancer syndrome https://github.com/monarch-initiative/mondo/issues/6006 MONDO:0100256 Germline pathogenic or likely pathogenic variants in the CTNNA1 gene predispose to hereditary diffuse gastric cancer and lobular breast cancer, a cancer susceptibility syndrome inherited in an autosomal dominant pattern. GARD:0026099