Investigation of genetic susceptibility factors for human longevity - a targeted nonsynonymous SNP study

Twin studies have shown that longevity in humans is moderately heritable with a genetic component of 25-32%. Experimental model organisms point to the existence of core survival and anti-ageing pathways that have been conserved throughout evolution. It has been shown that mutations in single genes involved in these pathways can either delay or accelerate the ageing process and that many of these genes and pathways are also present in humans. Here, we performed a targeted investigation of selected genes (i) involved in longevity pathways (insulin receptor/insulin-like growth factor-I signaling and energy metabolism, intracellular signaling, apoptosis and stress response) and (ii) in which mutations lead to genetic perturbations in animal models or human diseases. Altogether, we tested 500 nonsynonymous single nucleotide polymorphisms (SNPs) in 343 candidate genes for association with the longevity phenotype in a German sample comprising about 400 centenarians and an equal number of younger control subjects. Thus, this study presents one of the largest candidate studies in human genetic longevity research conducted to-date. The three top-ranking markers, which are located in the genes DUSP6, NALP1 and PERP, revealed p-values≤0.01 in the allelic case-control comparisons. Although the association signals in Germans were not replicated in an independent French sample, the large number of analysis results is deemed a valuable reference point for further genetic studies.