Time-course of translocation and dicentric frequencies in a radiation accident case.
OBJECTIVE
To assess the persistence of exchange aberrations measured by FISH chromosome painting after accidental radiation exposure.


METHODS
Chromosome analyses were carried out in peripheral lymphocytes of a 13-year-old boy exposed to protracted low dose-rate whole-body and short-time partial-body irradiation from a radiation accident in Estonia in 1994. Up to November 1998, the frequencies of translocations and dicentrics were periodically measured using FISH chromosome painting of the target chromosomes 1, 4 and 12, with a simultaneous pancentromeric probe.


RESULTS
For the yields of dicentrics, an expected rapid temporal decline was found with a half-time of 14.2+/-1.9 months. The yields of reciprocal translocations also revealed a gradual but significant reduction with a half-time of 51.7+/-12.7 months.


CONCLUSIONS
An unchanged temporal persistence of so-called stable translocations cannot be assumed. Any significant reduction of this aberration type with time obviously limits the application of FISH-based translocation measurements for reliable long-term biodosimetry after combined protracted whole-body and partial-body radiation exposure.
Bauchinger
M
M
GSF-National Research Center for Environment and Health, Institute of Radiobiology, Ingolstädter Landstr. 1, D-85764 Neuherberg, Germany.
Schmid
E
E
Braselmann
H
H
D000293:Adolescent; D002869:Chromosome Aberrations; D020223:Chromosome Painting; D004307:Dose-Response Relationship, Radiation; D004957:Estonia; D006801:Humans; D008214:Lymphocytes / Q000528:radiation effects / Q000648:ultrastructure; D008297:Male; D018788:Radioactive Hazard Release; D014178:Translocation, Genetic / Q000528:radiation effects*; D014916:Whole-Body Irradiation