Genetic factors play a role in individual differences in
pain experience. Here, we performed a genome-wide association study (GWAS) to identify novel loci regulating
pain processing. We conducted a 2-stage GWAS and the candidate single-nucleotide polymorphisms (SNPs) association study on
pain experience using an exploratory cohort of patients with
cancer pain. The confirmatory cohort comprised of participants from the general population with and without habitual use of
analgesic medication. In the exploratory cohort, we evaluated
pain intensity using a numerical rating scale, recorded daily
opioid dosages, and calculated
pain reduction rate. In the confirmatory cohort,
pain experience was defined as habitual nonsteroidal anti-inflammatory
drug usage. Using linear regression models, we identified candidate SNP in the exploratory samples, and tested the association between phenotype and experienced
pain in the confirmatory samples. We found 1 novel SNP (rs11764598)-located on the gene encoding for
pleiotrophin on chromosome 7-that passed the genome-wide suggestive significance at 20% false discovery rate (FDR) correction in the exploratory samples of patients with
cancer pain (P = 1.31 × 10-7, FDR = 0.101). We confirmed its significant association with daily
analgesic usage in the confirmatory cohort (P = .028), although the minor allele affected
pain experience in an opposite manner. We identified a novel genetic variant associated with
pain experience. Further studies are required to validate the role of
pleiotrophin in
pain processing.