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

Table 2: Association statistics for 36 haplotype-tagging single-nucleotide polymorphisms (htSNPs) in FOXO1, FOXO4, and FOXO6 in German female LLI and controls.FOXO1 gene study are presented in this text. The study analyzed the association between FOXO gene family members (FOXO1, FOXO4, and FOXO6) and human longevity in German and Italian populations. The study did not find any evidence of an association between FOXO1 variants and human longevity in Germans or Italians. However, two samples of female Han Chinese showed association signals for the FOXO1 SNPs rs2755209 and rs2755213. The study suggests that there may be a continent-specific effect on longevity association with FOXO1 variants. Replications with more extensive DNA collections of, for instance, Japanese origin would be helpful to confirm the Asian- and female-specific longevity association of FOXO1.age: 95.8 years) and 216 younger controls (5064 years, mean age: 59.6 years). The Chinese sample consisted of 402 controls (2069 years) and the Japanese sample consisted of 98 controls (2069 years). The German control group comprised 1010 individuals (6075 years; mean age: 66.8 years). All control individuals were recruited from the same geographic region as the LLI and were free of any known chronic diseases at the time of enrolment. The study was approved by the respective local ethics committees, and all participants gave written informed consent. Table 5 shows the minor allele frequencies of FOXO1 SNPs in German, Italian, Chinese, and Japanese controls.The study analyzed 81 Southern Italian centenarians (mean age: 98.39 years) and 216 younger controls (mean age: 31.06 years) obtained from the Southern Italian Centenarian Study (SICS), enrolled by Associazione Longevita` (Anselmi et al., 2009). The demographic and clinical characteristics of SICS LLI were thoroughly investigated, and all subjects gave written informed consent to the study, which was approved by the Institutional Review Board of the Istituto di Ricovero e Cura a Carattere Scientifico, Multimedica, Milano, Italy.

The associated SNPs from Li et al. (2009) are in bold. "miF" stands for minor allele frequency, and "NA" means that no information is available. Data from Li et al. (2009) and Kojima et al. were used to determine that SNP rs2297626 is in strong linkage disequilibrium with rs17630266 (r2 = 0.95, using JPT HapMap data). Genotyping of the German samples was performed using the SNPlexTM Genotyping System and TaqMan SNP Genotyping Assays (both Applied Biosystems, Foster City, CA, USA) on an automated platform (Hampe et al., 2001). For quality control purposes, positive controls on each genotyping plate were checked for consistency. All SNPs were tested for deviation from the Hardy-Weinberg equilibrium, and the call rate for each marker exceeded 95.8%.

The LD structure of FOXO1 in Germans (A), Italians (B), Chinese (C), and Japanese (D) was analyzed using single-nucleotide polymorphisms used in the study of Chinese individuals by Li et al. (2009), based on linkage disequilibrium plots generated with Haploview using HapMap data of Han Chinese (CHB) and Japanese (JPT) as well as data of German and Italian control individuals from this study.

Genotyping of SICS individuals was carried out with the Infinium II Assay-HumanHap 317K duo BeadChip system (Illumina, San Diego, CA, USA) using standard protocols. Individual samples and markers showing a genotyping rate lower than 93% and 95%, respectively, were excluded. Imputation of unobserved genotypes was performed using Impute, version 0.5 (Marchini et al., 2007) with the HapMap CEU release 24 reference panel (http://www.hapmap.org/).

Further studies are needed to clarify in more detail the in vivo roles of the FOXO genes, particularly FOXO3A, in human longevity.

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