Replication of an association of variation in the FOXO3A gene with human longevity using both case–control and longitudinal data

Mette Soerensen,1,2 Serena Dato,1,2,3 Kaare Christensen,1 Matt McGue,1,4 Tinna Stevnsner,5 Vilhelm A. Bohr,5,6 and Lene Christiansen1,2

Vilhelm A. Bohr,

,

and Lene Christiansen

,

The Danish Aging Research Center, Epidemiology, Institute of Public Health, University of Southern Denmark, Odense C, Denmark

Department of Clinical Genetics, Odense University Hospital, Odense C, Denmark

Department of Cell Biology, University of Calabria, Rende (Cs), Italy

Department of Psychology, University of Minnesota, MN, USA

The Danish Aging Research Center, Department of Molecular Biology, University of Aarhus, Aarhus C, Denmark

Laboratory of Molecular Gerontology, National Institute on Aging, National Institute of Health, Baltimore, MD, USA

Introduction

Genetic factors contribute to the variation in human life span by approximately 25% (Herskind et al. 1996), a contribution believed to be minimal before age 60 years and most profound from age 85 years onwards (Hjelmborg et al. 2006). Candidate longevity genes encode proteins involved in several biological processes including the insulin⁄IGF-1 signaling pathway (Chris- tensen et al. 2006), in which the transcription factor forkhead box O3A (Foxo3a) is of key importance.

Summary

Variation in the gene encoding Foxo3a (FOXO3A) has previ- ously been reported to be associated with human longevity. Willcox et al. (2008) first reported on the associations of FOXO3A single nucleotide polymorphisms (SNPs) with longevity in male Americans of Japanese ancestry (rs2764264 (P-value (P) = 0.0002), rs13217795 (P = 0.0006) and rs2802292 (P < 0.0001)), associations which were subsequently confirmed (with effects pointing in the same direction) in Italian, American (northern and western European ancestry), Chinese and Ger- man populations (Anselmi et al. 2009; Flachsbart et al. 2009; Li et al. 2009; Pawlikowska et al. 2009). These studies reported 6 of 16 tagging SNPs (five specific to males and one to females) (Anselmi et al. 2009), 3 of 16 tagging SNPs (both genders) (Flachsbart et al. 2009), 2 of 16 tagging SNPs (specific to females) (Pawlikowska et al. 2009), and 3 of 3 tagging SNPs (both genders) (Li et al. 2009) to be associated with longevity. Furthermore, two studies reported on the associations of FOXO3A haplotypes with longevity (Anselmi et al. 2009; Li et al. 2009).

Genetic variation in FOXO3A has previously been associ- ated with human longevity. Studies published so far have been case–control studies and hence vulnerable to bias introduced by cohort effects. In this study we extended the previous findings in the cohorts of oldest old Danes (the Danish 1905 cohort, N = 1089) and middle-aged Danes (N = 736), applying a longitudinal study design as well as the case–control study design. Fifteen SNPs were chosen in order to cover the known common variation in FOXO3A. Comparing SNP frequencies in the oldest old with middle-aged individuals, we found association (after correction for multiple testing) of eight SNPs; 4 (rs13217795, rs2764264, rs479744, and rs9400239) previ- ously reported to be associated with longevity and four novel SNPs (rs12206094, rs13220810, rs7762395, and rs9486902 (corrected P-values 0.001–0.044). Moreover, we found association of the haplotypes TAC and CAC of rs9486902, rs10499051, and rs12206094 (corrected P-values: 0.01–0.03) with longevity. Finally, we here present data applying a longitudinal study design; when using follow- up survival data on the oldest old in a longitudinal analysis, we found no SNPs to remain significant after the correction for multiple testing (Bonferroni correction).

ies (comparing oldest old to younger controls), raising con- cerns about possible cohort effects introducing bias (Beekman et al. 2006; Christensen et al. 2006). In this study we aimed to add further support and to extend the evidence for a role of FOXO3A in longevity by investigating 15 FOXO3A SNPs covering the known common genetic variation in FOXO3A in two populations of middle-aged and oldest old Danes, applying the case–control study design (middle- aged versus oldest old) as well as a longitudinal study design (oldest old only).

Mette Soerensen, The Danish Aging Research Center, Epidemiology, Insti- tute of Public Health, University of Southern Denmark, J.B. Winsloews Vej 9B, 5000 Odense C, Denmark. Tel.: +45 6541 2822; fax: +45 6541 4875;

Accepted for publication 29 August 2010

frequencies, nominally significantly differences were found for rs12206094, rs13220810, rs479744, rs7762395, and rs9486902 (both genders combined) and for rs12206094, rs13217795, rs13220810, rs2764264, rs2802292, rs3800231, rs479744, rs7762395, rs9398172, rs9400239, and rs9486902 (males only). No nominally significant effects (either by PCCA or PCCG) were found for the females.

Results

Genotype and allele frequencies