ABSTRACT
Intron 3 16 bp duplication polymorphism of p53 gene has been associated with increased risk of colorectal, breast and lung cancers. Nevertheless there are inconsistent results and we need more studies to understand the importance of this polymorphism in increased risk of cancer predisposition. The aim of this study was to assess the association of 16 bp duplication polymorphism of p53 with thyroid cancer risk. Material and This case-control study included 105 thyroid patients and 170 controls. Cases and controls were matched for age, sex and ethnicity. Genomic DNA was extracted from peripheral blood samples and tumor tissues. P53 PIN3 genotype was determined using PCR products length analysis on polyacrylamide gel. Result: In the control and case groups, 62.9% and 53.3% had no 16 bp insertion, 7.1% and 8.6% had insertion in both p53 alleles and 30% and 38.1% were heterozygous, respectively. There were no significant differences between the case and control groups in regard to genotype frequencies as well as allelic frequencies. According to the results of our study PIN3 16 bp duplication polymorphism of p53 could not be considered as a risk factor for predisposition to thyroid cancer in northwest of Iran