We failed to replicate findings for the top SNP either in 1822 white participants from 3C-Dijon for whom mean age was 72.5 years and 9.4% had at least 1 MRI-infarct (MAF=22%, OR=0.99, 95% CI=0.76–1.29, p=0.92) or in 644 African-American participants from the ARIC study for whom mean age was 61.5 years and 15.5% had at least 1 MRI-infarct (MAF=6.5%, OR=1.26, 95% CI=0.74–2.15, p=0.40). However, four other SNPs in intron 3 of MACROD2 within 50–151kb from rs2208454 were significantly associated with MRI-infarcts in the African-American sample (rs7268327, p=0.045; rs1998237, p=0.006; rs4464346, p=0.0006; rs8116105, p=0.01). In the discovery sample, rs8116105 was also associated with MRI-infarcts, although the direction of the association was opposite (p=0.02) (Appendix, Table B). The linkage disequilibrium pattern in this region differs substantially between Caucasian and African populations (Figure 4). Details on the replication effort are contained in the Appendix, Section 7.
