[Idiopathic familial erythrocytosis. Report on a family with autosomal dominant inheritance].

An autosomal erythrocytosis, inherited as a dominant, occurred in seven members of a family. The propositus was first diagnosed as having erythrocytosis at 26 years of age. He had headaches and marked plethora. Polycythaemia vera and secondary erythrocytosis of known cause were excluded. Erythropoietin level was not elevated. Two of his three children were also found to have erythrocytosis. As in this family, the disease is characterized in middle age by hypertension, cardiovascular and thromboembolic phenomena, as well as abnormal bleeding. For over eight years the propositus has been successfully treated with repeated venous blood lettings.