Dystrophinopathies.

The dystrophinopathies fall along a spectrum of muscular dystrophy phenotypes, with variable involvement of skeletal and cardiac muscle. The diagnosis of dystrophinopathy should be suspected in any patient with a highly elevated creatine kinase level beyond the context of rhabdomyolysis secondary to toxic or metabolic myopathy. Genetic testing for dystrophinopathy is highly sensitive and specific, and identifying a proband will often lead to implications for several relatives at risk for cardiomyopathy, weakness, or anesthetic reactions. Management of the dystrophinopathies is focused primarily on supportive care, although steroid therapy has changed the natural history of Duchenne muscular dystrophy and it is now standard-of-care internationally. An exciting and ongoing area of investigation of the dystrophinopathies is focused on the potential for altering gene expression, as a way of improving muscle health and slowing the rate of muscle degeneration. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.