Genetics of Musculoskeletal Exercise-Related Phenotypes.

Genetic factors have been shown to associate with various exercise-related phenotypes, including exercise performance, adaptation to training and sports injuries. The genes implicated in the pathogenesis of musculoskeletal soft-tissue injuries all code for either structural components or regulatory components of the extracellular matrix. It has been hypothesized that these genetic associations with injuries are due to genetically regulated changes in mechanical properties of musculoskeletal soft tissue. Thus, the objective of this review is to highlight the research which has advanced our understanding of how genetic variation within these structural genes affects the properties of our connective tissue. The genetics of various exercise-related phenotypes, such as range of motion, endurance performance and exercise-associated muscle cramps, are reviewed. Lastly, a model is presented where genetic variations within a collagen-encoding gene result in a continuum of phenotype ranging from a normal tissue to a seriously deleterious or lethal disorder.