Etiology of childhood leukemia: a possible alternative to the Greaves hypothesis.

Whenever a country has experienced a significant decrease in infant mortality there has always been a concomitant increase in childhood cases of acute lymphoblastic leukemia (ALL). According to Greaves, this increase is the result of a new type of leukemia, which was first seen in Britain between 1920 and 1940. An alternative hypothesis is proposed which assumes that, for childhood cases of ALL, infections are competing causes of death and for juvenile myeloid leukemia (JML) the principal competitor is the sudden infant death syndrome (SIDS). The SIDS association is the result of JML originating in undifferentiated (erythro-myeloid) stem cells and having faulty erythropoiesis as a side effect. With this congenital anomaly as part of the disease process, the low oxygen pressures of deep sleep may be sufficient to cause sudden death from tissue anoxia.