Evidence of clastogens in acute leukemia. Chromosomal abnormalities in healthy parents of congenital leukemic patients.

If leukemia is caused by an "agent" which can pass through the placenta, it could produce leukemic transformation in the maternal cells. Cytogenetic studies were carried out in 5 acute lymphoblastic leukemic children and their parents. Significant abnormalities were found in 3 of the fathers, 4 of the mothers, and all the leukemic children. All but one abnormal metaphase from the mothers of the 2 leukemic boys had a XX sex pattern, indicating that these abnormal metaphases originated in the mother and probably were caused by a chromosomal breaking agent. The abnormal metaphases found in the fathers suggests that they too were exposed to this agent. Therefore, this agent must be present in the immediate environment, and this can pass from the material circulation to the fetus through the placenta and effect the fetus cells. The failure of the infant to eradicate these abnormal cells results in the phenotypical expression of clinical leukemia.