Familial malignant blood diseases: lessons learned from a 20-year period

Here we report the conclusions of our 20-year experience with familial occurrence of malignant hematological disorders. Between 1 January 1983 and 1 January 2003, 35 families of multigenerational hematological malignancies were identified in first or second degree relatives. We established the following conclusions in subsequent generations: (i) a significantly earlier onset (P < 0.0001); (ii) an equal or enhanced severity of the disease; and (iii) higher relative risk in offsprings for different hematological disorders. We propose to use the term double acceleration when both phenomena (earlier onset and identical or enhanced severity) are experienced simultaneously. The data emphasize the need to use detailed cytogenetic and molecular biological studies to identify the underlying defects in cases where double acceleration can be verified.