Evaluation of a SNP map of 6q24-27 confirms diabetic nephropathy loci and identifies novel associations type 2 diabetes patients enriched with nephropathy from an African American population

Previously we performed a genome scan for type 2 diabetes (T2DM) using 638 African-American (AA) affected sibling pairs from 247 families; non-parametric linkage analysis suggested evidence of linkage at 6q24-27 (LOD 2.26). To comprehensively evaluate this region we performed a 2-stage association study by first constructing a SNP map of 754 SNPs selected from HapMap on the basis of linkage disequilibrium (LD) in 300 AAT2DM-ESRD subjects, 311 AA controls, 43 European American controls and 45 Yoruba Nigerian samples (Set 1). Replication analyses were conducted in an independent population of 283 AA T2DM-ESRD subjects and 282 AA controls (Set 2). In addition, we adjusted for the impact of admixture on association results by using ancestry informative markers (AIMs). In Stage 1, 137 (18.2%) SNPs showed nominal evidence of association (P