Clinical Therapeutic Management of Human Mitochondrial Disorders

Despite recent advances in the elucidation of etiology and pathogenesis of mitochondrial disorders, their therapeutic management remains challenging. This review focuses on currently available therapeutic options for human mitochondrial disorders. Current treatment of mitochondrial disorders relies on symptomatic, multidisciplinary therapies of various manifestations in organs such as the brain, muscle, nerves, eyes, ears, endocrine organs, heart, intestines, kidneys, lungs, bones, bone marrow, cartilage, immune system, and skin. If respiratory chain functions are primarily or secondarily impaired, antioxidants or cofactors should be additionally given one by one. All patients with mitochondrial disorders should be offered an individually tailored diet and physical training program. Irrespective of the pathogenesis, all patients with mitochondrial disorders should avoid exposure to mitochondrion-toxic agents and environments. Specific treatment can be offered for stroke-like episodes, mitochondrial epilepsy, mitochondrial neurogastrointestinal encephalopathy, Leber hereditary optic neuropathy, thiamine-responsive Leigh syndrome, primary coenzyme Q deficiency, primary carnitine deficiency, Friedreich ataxia, ethylmalonic encephalopathy, acyl-CoA dehydrogenase deficiency, pyruvate dehydrogenase deficiency, and hereditary vitamin E deficiency. Preventing the transmission of mitochondrial DNA-related mitochondrial disorders can be achieved by mitochondrion replacement therapy (spindle transfer, pronuclear transfer). In conclusion, specific and nonspecific therapies for human mitochondrial disorders are available, and beneficial effects have been anecdotally reported. However, double-blind, placebo-controlled studies to confirm effectiveness are lacking for the majority of the measures applied to mitochondrial disorders. Transmission of certain mitochondrial disorders can be prevented by mitochondrion replacement therapy. A multidisciplinary approach is required to meet the therapeutic challenges of patients with mitochondrial disorders.