Leukaemia in children and their grandparents: studies of immune function in six families.

Seven of 500 children with acute leukaemia seen over a 15-year period were known to have a close relative with leukaemia or lymphoma. In each case the affected relative was a grandparent of the child, six of the seven being paternal grandparents. Investigation of thses six families showed that the fathers, who had two affected first-degree relatives, had lower lymphocyte counts and higher serum IgA concentrations than paired controls. Atopy, repeated infections and rheumatic disease were common amongst the parents and their sibs. The findings suggest a possible immunodeficiency basis for leukaemia in these families and perhaps also for acute lymphoblastic leukaemia of childhood in general. In the only family in which three generations, including both leukaemic patients, were available for HL-A typing, the affected grandson had not inherited either of his affected grandmother's haplotypes.