Inheritance of human longevity in Iceland

The idea that human longevity is influenced by genetic factors has recently received strong support from work on other species. On the basis of partia l population studies and selected kinships, significant correlations betwee n the ages of parents and offspring have been reported, and some but not ai l twin studies have confirmed that human longevity is moderately inherited. However, studies based upon a relatively small proportion of a population are susceptible to sampling error and selection bias. Here we report the us e of a comprehensive population-based computerised genealogy database to ex amine multigenerational relationships among those who live to the 95th perc entile in Iceland. We have developed a clustering tool which can generate l arge extended pedigrees connecting individuals from any list using the gene alogy database. First degree relatives of those living to the 95th percenti le are almost twice as likely to live to the 95th percentile compared with controls. Furthermore, we have developed an algorithm which we have named t he Minimum Founder Test (MFT) to examine the degree of relatedness of any p opulation-based list of individuals to estimate whether a trait has a famil ial component. The data indicate that there is a significant genetic compon ent to longevity. In addition, age-specific death rates are significantly l ower in the offspring of long-lived parents compared with controls, especia lly after age 70.