In skeletal muscle samples from EBS-MD patients (12,13), as well as from muscle-restricted conditional plectin knockout mice (MCK-Cre/cKO) (14), remarkable mitochondrial alterations have been observed, including altered cristae structure and massive subsarcolemmal aggregation of mitochondria, and the presence of fibers with attenuated levels of mitochondria (15). The gene discussed is CKM; the disease is Menkes disease.