The heritability of human longevity: a population-based study of 2872 Danish twin pairs born 1870-1900.
The aim of this study was to explore, in a large and non-censored twin cohort, the nature (i.e., additive versus non-additive) and magnitude (i.e., heritability) of genetic influences on inter-individual differences in human longevity. The sample comprised all identified and traced non-emigrant like-sex twin pairs born in Denmark during the period 1870-1900 with a zygosity diagnosis and both members of the pairs surviving the age of 15 years. A total of 2872 pairs were included. Age at death was obtained from the Danish Central Person Register, the Danish Cause-of-Death Register and various other registers. The sample was almost non-censored on the date of the last follow-up (May 1, 1994), all but 0.6% had died, leaving a total of 2872 pairs for analysis. Proportions of variance attributable to genetic and environmental factors were assessed from variance-covariance matrices using the structural equation model approach. The most parsimonious explanation of the data was provided by a model that included genetic dominance (non-additive genetic effects caused by interaction within gene loci) and non-shared environmental factors (environmental factors that are individual-specific and not shared in a family). The heritability of longevity was estimated to be 0.26 for males and 0.23 for females. The small sex-difference was caused by a greater impact of non-shared environmental factors in the females. Heritability was found to be constant over the three 10-year birth cohorts included. Thus, longevity seems to be only moderately heritable. The nature of genetic influences on longevity is probably non-additive and environmental influences non-shared. There is no evidence for an impact of shared (family) environment.
Herskind
A M
AM
Centre for Health and Social Policy, Institute of Community Health, Odense University, Denmark.
McGue
M
M
Holm
N V
NV
Sørensen
T I
TI
Harvald
B
B
Vaupel
J W
JW
D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D003718:Denmark; D005260:Female; D006801:Humans; D008136:Longevity / Q000235:genetics*; D008297:Male; D008957:Models, Genetic; D014427:Twins