[Genetics and hemopoietic neoplasia].

Genetic factors suspected in the etiology of human hemopoietic neoplasia, such as leukemia, lymphoma and multiple myeloma, are reviewed. High incidence of consanguineous marriage was found in parents of familial leukemia in siblings. It was also noted that the age of patients with familial leukemia in children of consanguineous parents was younger than that of cases whose parents were not related. These findings suggest that genetic factors may play an important role in the etiology of familial leukemia in siblings. According to the frequencies of familial aggregations in close relatives, the genetic relationships were supposed to be important in chronic lymphocytic leukemia and acute leukemia, but not in chronic granulocytic leukemia. Increased prevalence of autoimmune diseases in relatives of leukemic patients suggests a possibility of genetic immunodeficiency as a common etiologic factor in both diseases. Immunodeficiency was found in unaffected relatives of patients with familial leukemia and lymphoma. Genetic factors were also suggested by the familial occurrences of multiple myeloma and primary macroglobulinemia, and the incidence of benign monoclonal gammopathy in relatives of patients with these diseases. HLA studies revealed the increased frequencies of A2 in acute lymphocytic leukemia, of B5 and B18 in Hodgkin's disease, and of A5 and B18 in multiple myeloma. From such relationships existing between familial immunodeficiencies and hemopoietic neoplasia, genes regulating the immune responsiveness might be involved in susceptibility to these diseases.