Results

In this study, 36 haplotype-tagging SNPs (htSNPs) in the gene regions of FOXO1, FOXO4, and FOXO6 were analyzed for asso- ciation with human longevity. The polymorphisms were spaced across the entire genes, covering the majority of the allelic varia- tion. For none of the SNPs, a significant deviation from Hardy– Weinberg equilibrium (HWE) was found in the control popula- tion (P > 0.02). Single-marker comparisons did not show a significant association in any of the tested SNPs, neither for the complete sample of LLI (Table 1) nor the female (Table 2) or male subgroup (data not shown). A subsequent haplotype- based association analysis using a sliding window with pairs of consecutive SNPs revealed no association in any of the three genes with human longevity (data not shown).

Here, we performed a comprehensive analysis of FOXO1, FOXO4, and FOXO6 in a large group of 1447 long-lived individu- als (LLI, i.e. centenarians and nonagenarians) and 1029 younger

Table 1 Association statistics for 36 haplotype-tagging single-nucleotide polymorphisms (htSNPs)in FOXO1,FOXO4, and FOXO6 in German LLI and controls

Gene Chr. SNP bp minAF LI minAF controls P allele P geno OR (95% C.I.) FOXO1 13 rs2701893 40023636 0.349 0.353 0.772 0.520 0.98 (0.87–1.11) FOXO1 13 rs2721047 40025682 0.086 0.097 0.177 0.246 0.87 (0.72–1.06) FOXO1 13 rs17446593 40026085 0.170 0.181 0.338 0.631 0.93 (0.80–1.08) FOXO1 13 rs2755209 40035804 0.373 0.377 0.770 0.274 0.98 (0.87–1.11) FOXO1 13 rs1078892 40036020 0.187 0.193 0.589 0.425 0.96 (0.83–1.11) FOXO1 13 rs2701859 40039232 0.252 0.272 0.117 0.059 0.90 (0.79–1.03) FOXO1 13 rs12865518 40041190 0.250 0.237 0.307 0.345 1.07 (0.94–1.23) FOXO1 13 rs2721069 40041720 0.310 0.325 0.251 0.187 0.93 (0.82–1.05) FOXO1 13 rs2755213 40044301 0.090 0.094 0.626 0.876 0.95 (0.78–1.16) FOXO1 13 rs2701880 40048505 0.060 0.071 0.120 NA 0.83 (0.66–1.05) FOXO1 13 rs2951787 40059770 0.384 0.376 0.600 0.834 1.03 (0.92–1.16) FOXO1 13 rs2984121 40059979 0.185 0.178 0.556 0.823 1.05 (0.90–1.21) FOXO1 13 rs2721044 40060225 0.307 0.330 0.097 0.074 0.90 (0.80–1.02) FOXO1 13 rs4943794 40071408 0.211 0.223 0.313 0.457 0.93 (0.81–1.07) FOXO1 13 rs1986649 40076824 0.211 0.225 0.229 0.434 0.92 (0.80–1.06) FOXO1 13 rs17630266 40092032 0.036 0.033 0.510 NA 1.11 (0.81–1.52) FOXO1 13 rs12876443 40094877 0.107 0.107 0.989 0.871 1.00 (0.83–1.20) FOXO1 13 rs7981045 40107236 0.273 0.261 0.349 0.550 1.06 (0.93–1.21) FOXO1 13 rs9603776 40121886 0.025 0.024 0.778 NA 1.05 (0.73–1.52) FOXO4 X rs12013673 70233824 0.437 0.443 0.696 0.548 0.98 (0.86–1.10) FOXO4 X rs5981072 70236267 0.299 0.311 0.368 0.976 0.94 (0.83–1.07) FOXO6 1 rs11585393 41602844 0.301 0.293 0.531 0.466 1.04 (0.92–1.18) FOXO6 1 rs7539614 41603634 0.444 0.439 0.739 0.904 1.02 (0.91–1.15) FOXO6 1 rs7547654 41603948 0.458 0.440 0.200 0.356 1.08 (0.96–1.21) FOXO6 1 rs11581271 41607648 0.401 0.423 0.131 0.097 0.91 (0.81–1.03) FOXO6 1 rs1317558 41611670 0.119 0.108 0.257 0.195 1.11 (0.93–1.33) FOXO6 1 rs1317557 41611929 0.028 0.027 0.824 NA 1.04 (0.73–1.48) FOXO6 1 rs6693260 41612082 0.175 0.178 0.811 0.824 0.98 (0.85–1.14) FOXO6 1 rs4660532 41612784 0.331 0.348 0.224 0.461 0.93 (0.82–1.05) FOXO6 1 rs6690527 41614573 0.289 0.287 0.867 0.366 1.01 (0.89–1.15) FOXO6 1 rs4660192 41614937 0.458 0.464 0.663 0.833 0.97 (0.87–1.09) FOXO6 1 rs11209971 41616880 0.281 0.293 0.336 0.511 0.94 (0.83–1.07)

Chr., chromosome; bp, base-position of NCBI build 36; minAF, minor allele frequency; LLI, long-lived individuals; P allele, P value obtained from allele-based case–control comparison using a chi square-test with 1 degree of freedom (df); P geno, P value obtained from genotype-based case–control comparison using a chi square-test with 2 df; OR, estimated odds ratio for minor allele (based on whole sample); CI, 95% confidence interval of OR; NA, genotype- based case–control comparison was not conducted when there were fewer than five observations. Associated markers from the study of Li et al. (2009) are in bold.

Table 2 Association statistics for 36 haplotype-tagging single-nucleotide polymorphisms (htSNPs)in FOXO1,FOXO4, and FOXO6 in German female LLI and controls