Exon-level DRG Analysis of CA8

CA8 exon-level DRG analyses were run essentially as described elsewhere [35 (link)]. Briefly, bilateral L4 and L5 DRG were collected from a total of 214 brain-dead human subjects following asystole after consent of family members and snap-frozen. Genomic DNA was isolated and genotyped using Illumina’s Infinium Human Omni Express Exome-8 v1.2 chip (≈ 1M probes) and analyzed using Illumina Genome Studio 2011.1, as described. RNA was isolated from the same DRG samples frozen in TRIzol reagent (Qiagen, Austin, TX). Total RNA was analyzed using Affymetrix Human Transcriptome Array 2.0 (≈ 70K gene-level probes, ≈ 900K isoform-level probes). All statistical tests were performed with age, gender, sample’s average expression and the first two eigenvectors (from principal components analysis to capture racial/ethnic differences) per chromosome as covariates. eQTL discovery was performed on CA8 utilizing 20 exon-level probes that recognize 4 unique CA8 gene transcripts with an expression intensity level above 3. Dataset for eQTL results can be found at GSE78150 (Geo Accession; NCBI).