OBJECTIVETo investigate the association between oral neoplasm genetic susceptibility and genetic polymorphism of p53 intron 7.

METHODSThe intron 7 ApaI polymorphism of p53 was analyzed in 95 oral neoplasm patients and 105 healthy individuals by utilizing polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) genotyping assay technique, and direct sequencing was performed in 30 cases which were selected from the patients and controls by random sampling.

RESULTSIn oral neoplasms cases, haplotype combinations were T-G 43.2%, C-T 56.8%, and frequencies of genotype were T-G/T-G 15.8%, C-T/T-G 54.7%, C-T/C-T 29.5%, while in controls they were T-G 30.9%, C-T 69.1% and T-G/T-G 10.5%, C-T/T-G 41.0%, C-T/C-T 48.5%. There was a significant difference in the allelic frequency and the genotypical distributions between the oral neoplasm patients and the controls. The individuals with the T-G allele had a slight increasing neoplasm risk than individuals with C-T allele; the OR for T-G versus C-T was 1.69 (95% CI, 1.12 - 2.51). The risk of suffering from oral neoplasms was higher in the individuals of T-G/T-G genotype and of T-G/C-T genotype than in individuals of C-T/CT genotype with odds ratio of 2.48 versus 2.20.

CONCLUSIONSThere are two polymorphic points in the 7th intron of human p53 gene, which could be associated with genetic susceptibility of oral neoplasms. T-G allele may be the risk factor of oral neoplasms.