Large Genome-Wide Study Finds Only a Few Genetic Influences on Human Longevity

The influence of genetic variants on natural variations in human longevity is a very complex matter. The evidence to date supports a model in which thousands of genes have individually tiny, conditional effects. Near all associations identified in any given study population have failed to appear in any of the other study populations, and effect sizes for the very few longevity-associated genes that do appear in multiple studies are not large in the grand scheme of things. These variants provide a small increase in the odds of living to be very old, but the individuals bearing them are still diminished and damaged by aging. The genetics that determine how cellular metabolism gives rise to variations in aging are of great scientific interest, but there is nothing here that can act as the foundation for therapies that will help people to live significantly longer. The extent of the role of genetic variation in human lifespan has been widely debated, with estimates of broad sense heritability ranging from around 25% based on twin studies to around 16.1% based on large-scale population data. One very recent study suggests it is much lower still (less than 7%), pointing to assortative mating as the source of resemblance amongst kin. Despite this modest heritability, extensive research has gone into genome-wide association studies (GWAS) finding genetic variants influencing human survival. Only two robustly replicated, genome-wide significant associations (near APOE and FOX...
Source: Fight Aging! - Category: Research Authors: Tags: Daily News Source Type: blogs