Genotyping of CRP SNPs for Rheumatic Diseases

The seven CRP SNPs studied (rs11265257, rs1130864, rs1205, rs1800947, rs2808632, rs3093077 and rs876538) were selected on the basis of previous publications in rheumatic diseases [16 (link),18 (link),25 (link)] (Figure 1). The nucleotides are stated according to the plus strand. Genotyping was analyzed using the TaqMan OpenArray system from Applied Biosystems (Foster City, CA, USA). We typed one SNP with a custom-designed genotyping assay and six SNPs with a predesigned assay from Applied Biosystems (see Additional file 1: Table S1 for assay information). We have previously described this method in more detail [26 (link)]. OpenArray plates were manufactured by Applied Biosystems. A nontemplate control was introduced within each set of assays. TaqMan OpenArray Master Mix was used according to the manufacturer’s protocol. Samples were loaded into OpenArray plates using the OpenArray NT Autoloader and cycled using the GeneAmp PCR System 9700 thermal cycler with PCR conditions set according to the manufacturer’s protocol. The arrays were read using the OpenArray NT Imager, and the allele calls and scatterplots were generated with the genotyping software associated with the OpenArray system.