Genetics of Mitochondrial Myopathies

Abstract

Pearson syndrome. Clinical spectrum of mitochondrial disorders is broad, so consensus diagnostic criteria for mitochondrial disorders have been proposed for children 4) and adults. 5) Sequence map of human mitochondrial genome with its normal and patho genic variants is publicly available. 6) In this review, we will discuss genetic features of mitochondrial myopathies as well as their key findings. Representative syndromes will be described in detail and the less common entities will be summarized in Table 1. Mitochondrial myopathiesby mitochondrial genomic mutation Mitochondrion is a unique organelle in that it contains its own circular genome of 16.5 kb. 7) Mitochondrial genome encodes only 13 of 93 subunits for oxidative phosphorylation system. All 22 tRNAs and 2 rRNAs are on mitochondrial genome, while the other proteins including ribosomal proteins are imported

Isolated mitochondrial myopathy misdiagnosed as polymyositis

“…The genetic defects of mitochondrial myopathies can be classified according to the type of DNA mutation: deletions in mtDNA, duplication of mtDNA, point mutations in mtDNA, or other mutations in nuclear DNA. Mutations in genes relating to the replication of mtDNA or to respiratory chain reactions, such as the DNA polymerase gamma catalytic subunit and mtD-NA genes encoding cytochrome b (MTCYB), thymidine kinase 2 (TK2), and cytochrome oxidase (COX), have been implicated in mitochondrial myopathy [3,4] .…”