While GDF15 is not a general marker of myopathy, it has been found to be elevated in mitochondrial myopathy caused by mitochondrial translation defects.45–47 Serum GDF15 was analysed from disease-control GNE myopathy patients (n = 39) and BMD/DMD adult patients (>20 years, n = 34). The gene discussed is GDF15; the disease is Duchenne muscular dystrophy.