The genetics of skeletal muscle disorders in horses.

Horses are remarkable athletes and a fascinating species in which to study the genetic bases of athletic performance, skeletal muscle biology, and neuromuscular disease. Genetic selection in horses has resulted in many breeds that possess anatomical, physiological, and metabolic variations linked to speed, power, and endurance that are beginning to be defined at the molecular level. Along with the concentration of positive traits, equine breeding programs have also inadvertently concentrated heritable muscle diseases for which mutations impacting electrical conduction, muscle contraction, and energy metabolism within and across breeds have been characterized. The study of heritable muscle diseases in horses has provided exciting insights into the normal structure and function of muscle and important diagnostic tools for veterinarians. Results empower breeders and breed associations to make difficult decisions about how to use this information to improve the overall health and well-being of horses.