The genetics of gastritis and peptic ulcer.

Genetic studies help to explain the pathogenesis, natural history, and nosology of the spectrum of gastroduodenal disorders encompassed by atrophic gastritis-pernicious anemia, gastric cancer, and peptic ulcer. All these disorders aggregate within families, and twin and disease-association studies have demonstrated that this aggregation has a genetic basis. Modern genetic studies are demonstrating that each of these disorders comprises several different diseases, and that many of the biochemical, physiologic, or immunologic abnormalities in such patients have a genetic basis. Thus, family members at risk can be identified. The optimum therapy and prevention of these diseases should ultimately depend on the specific genetic predisposition of the individual patient and family, and the recognition of individual susceptibilities to specific environmental influences.