Periampullary, colorectal and gastric cancer in two siblings.

We describe a sibship affected by subsequent periampullary, colorectal and gastric carcinoma. Three of 4 siblings (2 males, 1 female) developed a periampullary carcinoma at the age of 20, and the 2 brothers subsequently had colorectal and gastric carcinoma. One of them also had familial adenomatous polyposis. There is suggestive evidence of vertical transmission of a gene predisposing to a hereditary colorectal carcinoma syndrome.