Sensitivity, specificity, and persistence of chromosome translocations for radiation biodosimetry

The analysis of chromosome translocations by fluorescence in situ hybridization ("whole chromosome painting") is the gold standard endpoint for radiation biological dosimetry. Translocation formation requires mis-repair of two or more DNA double-strand breaks, a critical class of damage that is efficiently induced by ionizing radiation in a dose-responsive manner. Translocations are widely used for radiation exposure assessment because they provide a sensitive detection system for low doses, show good specificity for radiation exposure, persist for decades, and are highly relevant to tumorigenesis. This paper provides a brief evaluation of the use of translocation analyses by chromosome painting for biological dosimetry following chronic or low-dose exposure to ionizing radiation.