Few instances of familial polycythemia have been reported. No thorough studies have been made of the families of patients with this condition.
Nichamin,1 in 1907, observed a patient with mild polycythemia whose mother and sister had enlargement of the spleen and cyanosis. No studies were made on the blood of the relatives.
Bernstein,2 in 1914, recorded what he believed to be the first published report of the familial incidence of polycythemia. The blood of the patient contained 12,500,000 red corpuscles per cubic millimeter and 140 per cent hemoglobin. There were splenomegally and cyanosis. The son of this patient did not have a palpable spleen, but his blood showed 7,500,000 red corpuscles and 120 per cent hemoglobin.
Tancré,3 in 1917, reported the occurrence of polycythemia in two sisters, one of whom had 13,000,000, and the other 6,100,000, red blood corpuscles per cubic millimeter of blood. He suggested the