Targeting 160 candidate genes for blood pressure regulation with a genome-wide genotyping array

The outcome of Genome-Wide Association Studies (GWAS) has
challenged the field of blood pressure (BP) genetics as previous
candidate genes have not been among the top loci in these scans. We
used Affymetrix 500K genotyping data of KORA S3 cohort (n = 1,644;
Southern-Germany) to address (i) SNP coverage in 160 BP candidate
genes; (ii) the evidence for associations with BP traits in
genome-wide and replication data, and haplotype analysis. In total,
160 gene regions (genic region+/-10 kb) covered 2,411 SNPs across
11.4 Mb. Marker densities in genes varied from 0 (n = 11) to 0.6
SNPs/kb. On average 52.5% of the HAPMAP SNPs per gene were
captured. No evidence for association with BP was obtained for
1,449 tested SNPs. Considerable associations (P50% of HAPMAP SNPs were tagged.
In general, genes with higher marker density (>0.2 SNPs/kb)
revealed a better chance to reach close to significance
associations. Although, none of the detected P-values remained
significant after Bonferroni correction (P