The explanation of gastrointestinal bleeding poses a threat to the diagnostic acumen of internists, surgeons, and general physicians. The cause of bleeding in a small percentage of cases remains obscure long after the initial symptom as revealed by anemia, hematemesis, or melena, among other items, is noted. Several years ago, Maloney1 estimated that possibly 10% of instances of gastro-intestinal bleeding might be due to unusual or exotic maladies. In the recent issue of the Archives of Internal Medicine, Manley and Skyring2 discuss selected heritable causes of gastrointestinal bleeding. The presentation was based upon cases reviewed in the Division of Medical Genetics and the Joseph Earle Moore Clinic of Johns Hopkins Hospital and University under the tutelage of Victor A. McKusick.
Probably the best known heritable disease with potential gastrointestinal bleeding is hereditary hemorrhagic telangiectasia (Osler-Rendu-Weber). The dyscrasia is inherited as an autosomal dominant trait. Bleeding, usually from the