GGCn polymorphism of eRF3a/GSPT1 gene and breast cancer susceptibility.

The significance of translation regulatory factors in elevating the risk of cancer has been recently recognized. Eukaryotic release factor 3a (eRF3a) is a translation termination protein that is encoded by G1 to S phase transition 1 gene (GSPT1). The eRF3a/GSPT1 exon 1 contains a trinucleotide GGC repeat coding for a polyglycine expansion in the N-terminal of the protein. In the present study, we determined the allelic length of the GGC(n) repeat in the eRF3a gene in 250 women with breast cancer and 250 age-matched controls. Our results show that the presence of the longer allele, 12-GGC, is correlated with threefold increased risk of breast cancer development. Our findings also suggest that women who are homozygous for 7-GGC allele are possibly at higher risk of developing breast cancer, especially before the age of 50. No significant effect of the allelic length of eRF3a/GSPT1 polymorphism on inheritance or the grade of this disease was observed.