Differences in the pain sensitivity of genetically identical twins are associated with differences in the way key pain genes are chemically modified, reports research published this week in Nature Communications. The results highlight the importance of such epigenetic changes in human diversity, and may inform our understanding of how pain is detected by the body.
The study, carried out by a consortium led by Tim Spector, is the latest to take advantage of a valuable genetic database of identical twins, known as the TwinsUK cohort. The team measured the ability of the twins to tolerate contact with a heated surface, and compared differences in heat sensitivity between twins with differences in their patterns of DNA methylation. They find that variation in the methylation of a gene encoding a temperature sensing protein, TRPA1, correlates with pain tolerance. Eight other genes also displayed an association with pain tolerance, but further work will be required to understand how these genes contribute to our ability to sense pain.