DNA damage repair and genetic polymorphisms: assessment of individual sensitivity and repair capacity.
OBJECTIVE
To study the repair capacity after X-ray irradiation in human peripheral blood cells of healthy subjects, in relation to their genotypes.


METHODS
The peripheral blood of 50 healthy subjects was irradiated in vitro with 2 Gy of X rays and the induced DNA damage was measured by Comet assay immediately after irradiation. DNA repair was detected by analyzing the cells at defined time intervals after the exposure. Furthermore, all subjects were genotyped for XRCC1, OGG1, and XPC genes.


RESULTS
After X-ray irradiation, persons bearing XRCC1 homozygous variant (codon 399) genotype exhibited significantly lower Tail DNA values than those bearing wild-type and heterozygous genotypes. These results are also confirmed at 30 and 60 min after irradiation. Furthermore, XPC heterozygous subjects (variant codon 939) showed lower residual DNA damage 60 min after irradiation compared with wild-type and homozygous genotypes.


CONCLUSIONS
The results of the present study show that polymorphisms in DNA repair genes could influence individual DNA repair capacity.
Cornetta
Tommaso
T
Department of Biology, Università degli Studi Roma TRE, Rome, Italy.
Festa
Fabiola
F
Testa
Antonella
A
Cozzi
Renata
R
D000328:Adult; D020552:Comet Assay; D004249:DNA Damage / Q000235:genetics; D045647:DNA Glycosylases / Q000235:genetics*; D004260:DNA Repair / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics*; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D011110:Polymorphism, Genetic; D000076105:X-ray Repair Cross Complementing Protein 1
D004268:DNA-Binding Proteins; D000076105:X-ray Repair Cross Complementing Protein 1; C000619371:XRCC1 protein, human; C086984:XPC protein, human; D045647:DNA Glycosylases; C479058:oxoguanine glycosylase 1, human