Deletion or loss of the long arm of chromosome 7 in myelodysplasia and acute myeloid leukaemia could indicate previous exposure to ionising radiation, says Dr Maryanne Gundestrup from the University of Copenhagen (
Researchers studied the karyotype of seven aircrew members who had acute myeloid leukaemia or myelodysplasia and found a deletion or a loss of chromosome 7 in four. The same abnormality was found in eight of 19 patients with leukaemia after radiotherapy alone. Both the aircrew and radiotherapy groups showed a statistical significant excess of chromosome abnormality when compared with the range of chromosome aberrations found in 761 patients with myelodysplasia or acute myeloid leukaemia from Lund, Sweden.
Dr Gundestrup comments that "larger studies will be needed to confirm a link between myelodysplasia and acute myeloid leukaemia in aircrew and exposure to cosmic radiation" but these results could suggest an indicator of previous exposure to ionising radiation.