Jd. Tucker et al., ON THE FREQUENCY OF CHROMOSOME EXCHANGES IN A CONTROL POPULATION MEASURED BY CHROMOSOME PAINTING, Mutation research. Section on environmental mutagenesis and related subjects, 313(2-3), 1994, pp. 193-202
Chromosome painting has been shown to be a valid and rapid method for
quantifying structural chromosome rearrangements in human lymphocytes.
The method is particularly useful for detecting stable aberrations wh
ich are difficult and expensive to quantify with classical methods. Th
e inherent stability of translocations has enabled them to be used as
a biodosimeter for chronic and temporally displaced exposure to radiat
ion. Translocations may also be useful for quantifying chronic exposur
e to other environmental agents which may result in an accumulation of
cytogenetic damage with age. Most exposures are chronic and occur at
low rates, and conventional cytogenetic methods such as dicentric anal
ysis are not expected to be informative. To understand the extent to w
hich age and lifestyle factors impact the frequency of stable aberrati
ons, we have performed chromosome painting on metaphase-arrested lymph
ocytes cultured from 47 healthy adults ranging in age from 19 to 77 ye
ars, and from umbilical cord blood obtained from eight healthy full-te
rm infants. All subjects had previously been screened to eliminate tho
se who had received significant occupational or accidental exposure to
radiation or chemicals, and none had received chemo- or radiotherapy.
Due to the infrequent occurrence of stable aberrations in peripheral
lymphocytes, we analyzed the equivalent of more than 1100 metaphase ce
lls from each of these 55 people. An average of one cell in 130 (0.77%
) was observed to have a translocation or a stable insertion. A signif
icant relationship between stable aberrations and the square of the ag
e is apparent (R(2) = 0.69, Y = 0.0615 + 0.000304 age(2); p < 0.00001)
. These results support the hypothesis that stable aberrations accumul
ate with time, and are likely to integrate adverse environmental expos
ure.