Genetico-mathematical analysis of the inheritance pattern of peptic ulcer disease. Direct methods of Weinberg. I. Method of probands and method of siblings.

Inheritance of ulcer disease was analyzed genetico-mathematically using two methods: the method of probands and the method of siblings. Families of 351 probands were enrolled in the study: 57 had type II and 27 type III gastric ulcer disease. 267 were with duodenal ulcer disease. The types of gastric ulcer were determined according to H. Johnson. A further 188 families of type I gastric ulcer probands were also studied. However, data from these are not included in the present study because our previous investigation has shown no genetic determination of this type of ulcer disease. The detailed segregation analysis employed in the study does not support the assumption of a monogenic type of disease inheritance. The values obtained for the coefficient of genetic proportion do not substantiate either autosomal-recessive or autosomal-dominant pattern of transmission. This refers both to ulcer disease in general and to the calculation of the coefficient depending on the type of disease and the type of familial predisposition of probands.