STABLE CHROMOSOME-ABERRATIONS 25 YEARS AFTER SEVERE ACCIDENTAL RADIATION EXPOSURE

A thorough cytogenetic analysis using G-banding was performed on 100 p eripheral blood lymphocytes from an individual who had been accidental ly exposed to radiation more than 25 years previously. More than 60% o f the analysed cells were found to possess one or more stable chromoso me aberrations (e.g. reciprocal translocations). Chromosomes 1 and 11 were more involved in these aberrations than would be expected from th e relative chromosome lengths. No identical stable aberrations were fo und, suggesting that, 25 years after near-lethal exposure, haemopoieti c stem cells display substantial diversity.