Association of IGF-1 gene (rs5742612) polymorphism with colorectal cancer

Insulin-like growth factor 1 has an important role in cell proliferation and growth. Polymorphism in IGF-1 gene changes the level of this hormone and increases the risk of colorectal cancer. The aim of this study is to assess the incidence of IGF-1 polymorphism rs5742612 in Iranian population and to investigate the influence of this polymorphism in increasing the risk of colorectal cancer. Genotyping of IGF-1 gene was performed in a series of 110 colorectal cancer patients and 110 controls by using polymerase chain reaction and restriction fragment length polymorphism genotyping (PCR-RFLP) assays. We calculated odds ratio and confidence interval (CI) of IGF-1 genotypes to determine if these polymorphisms are associated with colorectal cancer. No significant association was found between polymorphism of IGF-1 gene (rs5742612) and increased risk of colorectal cancer (p=0.92). The odds ratio for the heterozygous genotype CT versus the normal genotype CC was 1.3 (95% CI: 0.3-6.27) and the odds ratio for the mutant genotype TT versus the normal genotype CC was 0.0. The frequency of the mutant allele was 2.5%. These findings suggest that IGF-1 rs5742612 polymorphism is not associated with increased risk of colorectal cancer. (Quarterly Journal of Sabzevar University of Medical Sciences, Volume 19, Number 2, pp.109-115).