ABSTRACT
<p><b>OBJECTIVE</b>To investigate the association between oral neoplasm genetic susceptibility and genetic polymorphism of p53 intron 7.</p><p><b>METHODS</b>The 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.</p><p><b>RESULTS</b>In 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.</p><p><b>CONCLUSIONS</b>There 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.</p>