An inborn error of metabolism characterized by abnormal urinary excretion of myoglobin due to acute destruction of skeletal muscle fibers. The exact prevalence remains unknown. In the majority of cases, the disease manifests in childhood and is often triggered by exertion or infection (febrile illness). Hypertonia, muscle stiffness and muscle pain, impaired kidney function and elevated levels of serum creatine kinase are common clinical features. Mutations in the mitochondrial DNA-encoded cytochrome C oxidase genes (MT-CO1 and MT-CO2) should be considered in patients with recurrent myoglobinuria. Recently, mutations in the LPIN1 gene (chromosome 2p21) have been reported to have a causative role in three patients with recurrent episodes of myoglobinuria, originating from consanguineous families. The disorder may occur sporadically, or be inherited in either a recessive or dominant manner.