Abstract
Hereditary haemorrhagic teleangiectasia (Rendu-Osler-Weber disease) is an inborn error of vascular structure with multiple manifestations. Its incidence is about 1-2:100 000 in the European population. The incidence of telangiectases and/or fistula formation was estimated to be 1 in 10 carriers of the Osler trait. The findings in the family reported herewith suggest a much higher incidence if angiography is more frequently performed. Apart from the skin and mucous membrane, teleangiectases and/or arteriovenous fistulas may be present in the lungs, intestinal tract, spleen, kidney, brain, and bones. The liver apparently is more involved than was orginally suspected. The vascular derangement includes teleangiectases, arteriovenous fistulas, and connective tissue formation with fibrosis and atypical cirrhosis. In intestinal bleeding laser coagulation seems to be very efficient. The pathogenesis of teleangiectases is not known but involves several factors such as special formation of venules, capillaries and arterioles, abnormal perivascular connective tissue and endothelial cells.