[Congenital intrinsic factor deficiency. Apropos of 3 cases in a sibship].

Three familial cases of congenital intrinsic factor deficiency are reported: the stress is put on the interest of gastric investigations and especially of the quantity of intrinsic factor in the gastric juice when investigating megaloblastic anemia due to vitamin B12 deficiency. The study of the level of intrinsic factor in the gastric juice is proposed as a test for identifying carriers.