Distribution of myosin heavy chain isoforms in muscular dystrophy: Insights into disease pathology

Myosin heavy chain isoforms are an important component defining fiber type specific properties in skeletal muscle, such as oxidative versus glycolytic metabolism, rate of contraction, and fatigability. While the molecular mechanisms that underlie specification of the different fiber types are becoming clearer, how this programming becomes disrupted in muscular dystrophy and the functional consequences of fiber type changes in disease are not fully resolved. Fiber type changes in disease, with specific focus on muscular dystrophies caused by defects in the dystrophin glycoprotein complex, are discussed.