Fig. 1 Multipoint linkage results for all chromosomes. MHLOD for the dominant multipoint model (red or moderate gray line), recessive multipoint model (blue or darkest gray line), and

1.00. Upstream of the PARK2 association, seven FRA6E markers in high LD (r20 1.00) were moderate- ly associated with SA. These markers were located ~60 Mb upstream of mitogen-activated protein kinase, kinase 4 (MAP3K4) and downstream of plasminogen (PLG). However, there is low pairwise LD between these three associations (r2<0.01 between rs205990 and the other two blocks, r20 0.08 between the FRA6E blocks), indicating that the signals are independent.

chromosome 6, on chromosome 10, p< 3.1×10−5 on chromosome 16, p<1.0×10−4 on chromo- some 17, and p<4.4×10−5 on chromosome 20).

In addition to the association mapping under link- age peaks, all genotyped SNPs were analyzed to detect any genome-wide significant associations (Bonferroni corrected p<8×10−8). Quantile– quantile (q– q) plots (Online Resource Fig. 1) demonstrated little deviation from expectations. As summarized in the Manhattan plot (Online Resource Fig. 2), no associations exceeded this threshold, but the strongest results genome-wide (p<1×10−5) are summarized in Table 3. Ten of these SNPs are in the fragile site 6 (FRA6E) region on chromosome 6 and are less than 3 Mb from the regionally significant SNP on chromosome 6 (rs205590). Eight additional SNPs were further than 3 Mb. Stratification by state of residence indicated that associations were concentrated in Amish from Ohio, consistent with linkage results in the 6q region.

Discussion

We performed a GWAS examining linkage to and association with SA in the Amish and observed sug- gestive evidence for both at intergenic SNP rs205990 on chromosome 6. This marker survived interval-wide Bonferroni correction and is located between the genes QKI and PDE10A. Neither gene has been pre- viously associated with risk for SA or any other lon- gevity or aging trait. PDE10A is involved in neurologic cascades and has been associated with schizophrenia and Huntington’ s disease (Arnaud-

Three SNPs in the FRA6E region were in a gene, Parkinson juvenile disease protein 2 (PARK2), and are in high linkage disequilibrium (LD) (Online Resource Fig. 3) with each other with r2 ranging from 0.86 to

Table 3 Strongest MQLS results from binary trait analyses

SNP Chromosome Position (bp) MAF HWE p MQLS p Nearest SA Control Genes rs11585386 1 227085771 0.19 0.05 0.635 4.50×10−6 RHOU\RAB4A rs294588 5 162931093 0.49 0.26 0.400 1.05×10−6 MAT2B\LOC391844 rs12518984 5 162940090 0.45 0.25 0.724 7.80×10−6 MAT2B\LOC391844 rs1572438 6 803970 0.49 0.27 0.502 9.22×10−6 HUS1B\FOXQ1 rs6942089 6 80491598 0.30 0.47 0.112 7.30×10−6 SH3BGRL2\ELOVL4 rs9359390 6 80493147 0.30 0.49 0.269 3.38×10−6 SH3BGRL2\ELOVL4 rs2038292 6 80509889 0.39 0.40 0.349 6.08×10−6 SH3BGRL2\ELOVL4 rs2092745 6 80511550 0.40 0.39 0.276 7.33×10−6 SH3BGRL2\ELOVL4 rs6925255 6 80522843 0.29 0.49 0.274 1.18×10−6 SH3BGRL2\ELOVL4 rs932492 6 80531291 0.37 0.46 0.086 6.49×10−6 SH3BGRL2\ELOVL4 rs9443716 6 80543068 0.37 0.46 0.087 6.29×10−6 SH3BGRL2\ELOVL4 rs1247322 6 161250642 0.24 0.10 0.771 3.56×10−6 PLG\MAP3K4 rs1247320 6 161253771 0.24 0.10 0.771 3.56×10−6 PLG\MAP3K4 rs1247319 6 161253850 0.24 0.10 0.771 3.56×10−6 PLG\MAP3K4 rs1247318 6 161253927 0.24 0.10 0.771 2.89×10−6 PLG\MAP3K4 rs1247317 6 161254404 0.24 0.10 0.771 3.56×10−6 PLG\MAP3K4 rs1247316 6 161255135 0.24 0.10 0.771 3.56×10−6 PLG\MAP3K4 rs1247363 6 161262680 0.24 0.10 0.771 7.61×10−6 PLG\MAP3K4 rs16892673 6 161853925 0.21 0.06 0.651 4.69×10−6 PARK2 rs16892698 6 161863355 0.19 0.05 0.319 6.24×10−6 PARK2 rs16892700 6 161864569 0.19 0.05 0.319 6.24×10−6 PARK2 rs9918668 7 93529680 0.19 0.43 0.403 5.84×10−7 BET1\COL1A2 rs643473 12 128041892 0.19 0.40 0.863 9.42×10−6 LOC100129252\NLRP9P

Bold indicates a deviation from HWE bp base pair position from NCBI build 37.1, MAF minor allele frequency

bp base pair position from NCBI build 37.1, MAF minor allele frequency

complex disorders. In addition, the TSHR expression has previously associated with exceptional longevity in a previously published study of Ashkenazi Jewish centenarians, which may support a role for PDE10A in SA (Atzmon et al. 2009b). Although we observed strong evidence for linkage at three additional regions on chromosomes 10, 17, and 20, markers under these linkage peaks did not show individual evidence for association. This may be due to either lack of power to find association or it may be possibly due to segrega- tion of alleles in sub-pedigrees and not population- level association.

Lopez et al. 2008; Kehler 2011; Kleiman et al. 2011). A previously published genome-wide scan associating thyroid stimulating hormone (TSH) and thyroid levels with gene variants observed a strong association with PDE8A and PDE10A in age diverse populations (Sar- dinians, Tuscans, and Old Order Amish) (Arnaud- Lopez et al. 2008). The strongest association in this previously published study was in PDE8A; however, PDE10A is in the same enzyme family and is involved in the cyclic AMP (cAMP) and cyclic GMP signaling pathways. The PDE10A gene protein product has been found to be involved in the pathophysiology of human disease. TSH controls thyroid function through bind- ing of G protein coupled receptor, TSH receptor (TSHR), and cAMP production. TSH plays a role in muscle, bone, central nervous system, and heart phys- iology, and therefore may contribute to several

The SNPs with the strongest, but not genome-wide significant, evidence for association (p<1.00×10−5) were not located in genes and did not show evidence for linkage. Several of these markers are on chromo- some 6 within the FRA6E region, which is less than