A novel polymorphism in intron 6 of the human p53 gene: A possible association with colorectal cancer predisposition and susceptibility

We found a new polymorphic 8 base-pairs (bp) sequence in intron 6 (non-coding zone) of the p53 gene. Thirty two percent of blood samples from healthy people were heterozygotic for this polymorphism and displayed a NN' genotype, whereas 68% of the population is homozygotic for the N genotype. The rare homozygotic genotype N' was not found in any blood samples of patients with colorectal cancer. Analysis of the distribution of the new polymorphism in colorectal and breast tumor samples showed loss of heterozygosity (LOH). This LOH during tumor progression could exhibit predisposition to each one of the polymorphic alleles. The rare presentation of one allele, and the increased incidence of heterozygosity in patients with cancer, may suggest an association between this novel polymorphism with cancer predisposition and susceptibility.