Infinium beadchips

Genome-wide data for 472,049 SNPs genotyped at Texas Biomedical Research Institute on the Illumina Infinium Bead chips: HumanHap550v3, supplemented with HumanExon510Sv1; Human660W-Quadv1; Human1Mv1; and Human1M-Duov3 arrays on odd-numbered autosomes were provided for analysis. All SNPs used in the analyses were filtered for Mendelian errors, monomorphic SNPs [12 (link)], and Hardy-Weinberg equilibrium. Merlin was used to impute missing genotypes. For the SEM model prediction, we extracted previously identified SBP, diastolic blood pressure (DBP), and pulse pressure–associated SNPs [14 (link)–19 (link)] from previous GWA studies data and considered each SNP separately. SNPs were only included in SEM if each genotype had at least 30 individuals. The full genetic panel, including imputed genotypes, was used in the trajectory association analyses.

InfiniumBeadChips were manufactured by Illumina in a 24 × 1 format. For each sample, genomic DNA was extracted from freeze-dried needle tissue using a CTAB protocol (van der Beek et al. 1992 (link)) with minor modifications made for the processing of 96-well deep well plates. DNA concentrations were quantified on a 0.8% agarose gel. At the IMGM Laboratories GmbH, SNP genotyping was conducted according to the manufacturer’s recommendations and the microarray signals were detected on Illumina’s iScan System. All SNP data analyses were conducted using GenomeStudio v. 2011.1 (Illumina).