Significant association of TP53 Arg72Pro polymorphism in susceptibility to differentiated thyroid cancer.

Abstract

Among various polymorphic variants of TP53 gene, codon 72 polymorphism (Arg72Pro) has been found to be associated with cancer susceptibility, but only few studies have investigated their effect on thyroid cancer risk. A case control study was conducted to elucidate the possible role of this SNP as risk factor in thyroid cancer development and to examine its correlation with various clinicopathological variables. In this study, we tested the genotype distribution by PCR-RFLP in 140 thyroid cancer patients and 200 cancer-free controls from Kashmir Valley. Genotype frequencies of Arg/Arg (GG), Arg/Pro (GC), and Pro/Pro (CC) genotypes among cases were 0.286, 0.343 and 0.371 while in controls 0.45, 0.37 and 0.18 respectively. Proline allele frequency was significantly higher than arginine frequency in patient group (OR = 2.06, 95% C.I = 1.5-2.8). Significant association was found between variant genotype of codon 72 of TP53 gene and young age group, female gender, urban dwellers, non-smokers and patients with elevated TSH levels (P < 0.05). It is evident from our study that Arg72Pro SNP of TP53 gene is connected with higher susceptibility to thyroid cancer especially in young age group, female gender, non-smokers and patients with elevated TSH levels, hence, implicated in thyroid carcinogenesis.