Absence of association between SNPs in the promoter region of the insulin-like growth factor 1 (IGF-1) gene and longevity in the Han Chinese population.

Previous studies have indicated that genetic variations in the factors of insulin/insulin-like growth factor 1 (IGF-1) signaling pathway could influence human life-span by affecting IGF-1 levels. The promoter region of the IGF-1 gene is an obvious candidate and has not been studied clearly. To explore the potential role of the promoter region variation of IGF-1 gene in longevity, we investigated 485 longevity subjects and 392 younger individuals from Dujiangyan, China. By sequencing about 2.5 kb (kilo base pairs) upstream the transcription start site of exon 1 of the IGF-1 gene in 30 individuals from both groups respectively, we acquired three previously described SNPs (-439T/A (rs2288377), -541T/C (rs5742612) and -1246C/T (rs35767)). We examined the association between these three SNPs and longevity by comparing the distribution of genotypes, alleles, and haplotypes in both the longevity and control groups. None of these variants were found to be associated with longevity. Our results suggest that there is no association between SNPs in the promoter region of IGF-1 gene and longevity in the Han Chinese population.