SMARCA4 and Familial gastric cancer: Genetic tumor syndromes, such as Li-Fraumeni syndrome, Lynch syndrome, DICER1 syndrome, Hereditary Diffuse Gastric Cancer, Neurofibromatosis type 1, Peutz-Jeghers syndrome, PTEN hamartoma tumor syndrome, Tuberous Sclerosis, and pathogenic variants in NBN and SMARCA4, illustrate the genetic and phenotypic heterogeneity underlying inherited breast and gynecologic malignancies.