RT Journal T1 HEredity in human leukemia and its relation to cancer. JF Archives of Internal Medicine JO Archives of Internal Medicine YR 1949 FD September 1 VO 84 IS 3 SP 521 OP 521 DO 10.1001/archinte.1949.00230030163011 UL http://dx.doi.org/10.1001/archinte.1949.00230030163011 AB The pedigrees of 209 patients with leukemia were examined, and compared with those of a suitable control group of 200 subjects. Among the 4,041 relatives of the leukemic patients there were 17 cases of leukemia and 319 cases of cancer. Among the 3,641 relatives of the controls there were 2 cases of leukemia and 218 cases of cancer. The author concludes that a familial occurrence of leukemia is demonstrated. From statistical studies he states that the "cancer risk" is 31 per cent in relatives of patients with leukemia, as compared with 22 per cent in the control group. This difference is said to be significant. The study offers strong support for the operation of a genetic factor in the etiology of human leukemia. This is of interest because of the undoubted hereditary nature of certain types of animal leukemia.