Clinicopathological findings in mitochondrial disorders

Abstract

Mitochondrial encephalomyopathies have shifted from being regarded just a few years ago as a category of rare metabolic diseases to a current recognition that they are much more common than previously thought, are a large and heterogeneous group of distinct diseases, and that they may occur not only as primary biochemical and genetic defects, but also as secondary defects in a wide spectrum of both genetic and acquired diseases of the nervous system ranging from Pompe disease (glycogenosis II, acid maltase deficiency), spinal muscular atrophy, septo-optic-pituitary dysplasia, some inflammatory myopathies, and secondary to a broad range of drugs that include immunosuppressive and chemotherapeutic agents, statins and valproic acid. Most of the research on mitochondrial diseases has been generated, not surprisingly, in the countries with the greatest funding and biochemical laboratory resources for investigating them, including detailed biochemical and genetic studies, neuroimaging and neuropathological studies, mainly from western Europe and North America. It is therefore encouraging to see studies of mitochondrial diseases eminating also from countries with fewer resources, such as the paper by Selim et al. [1] from Egypt, in this current issue of the JPN.