This panel consists of 47 genes that may be considered in the evaluation of patients with elevated CK levels, muscle cramping and weakness, myoglobinuria, or rhabdomyolysis. The conditions included range in severity and include various forms of disorders of fatty acid and glycogen metabolism, mitochondrial disorders, muscular dystrophies, and others. Myopathic disorders presenting with leg cramps carry a risk of either rhabdomyolysis or progressive muscle weakness and can easily be missed Rhabdomyolysis results from the breakdown of skeletal muscle that may occur from a combination of environmental and genetic factors, and episodes can be triggered by a variety of factors. Initial symptoms may occur following strenuous exercise, infections, fasting, temperature extremes, or exposure to drugs or alcohol, and the signs of rhabdomyolysis include myoglobinuria, or darkened and discolored urine, that could lead to renal failure if left untreated. Some disorders that place individuals at risk for rhabdomyolysis are characterized by a "second-wind" phenomenon where initial exercise intolerance is overcome after a short period of rest. Susceptibility to malignant hyperthermia may also present with evidence of muscle breakdown after exposure to certain anesthetics, and this condition can be life-threatening without prompt recognition and treatment.
List of Genes and Associated Clinical Phenotypes