Genetic Variation as a Possible Explanation for the Heterogeneity of Pain in Tendinopathy: What can we learn from other pain syndromes?

Abstract

The mechanisms of pain in tendinopathy are unclear. Current theories implicate tendon structural changes, neovascularisation, inflammation or changes in central pain processing. As with other types of musculoskeletal pain, tendon pain has high interindividual variability and, as with other types of pain, this could be attributed to genetic variation. Notably, the association between certain genetic polymorphisms and susceptibility to tendinopathy is well established in the literature. Therefore, the investigation of the mechanisms of tendon pain should also extend to include genetic variation as a possible explanation for the clinical features of tendon pain. This review summarises the current knowledge on genetic contributors to chronic pain and highlights findings that are relevant to chronic tendon pain. In particular, based on the current hypotheses on the possible sources of tendon pain, it focuses on findings that relate to genes that encode structural connective tissue components, inflammatory markers, ion channels and catecholamines and how they may relate to chronic tendon pain. In the absence of a definitive mechanism of tendon pain, an a priori genetic approach that is guided by these current hypotheses may help elucidate the mechanisms of tendon pain which may allow a more rational approach to research and treatment.

Keywords

• tendon pain
• genetics
• extracellular matrix genes
• inflammation genes
• COMT