Mitochondrial diseases.
By convention, the term "mitochondrial diseases" refers to disorders of the mitochondrial respiratory chain, which is the only metabolic pathway in the cell that is under the dual control of the mitochondrial genome (mtDNA) and the nuclear genome (nDNA). Therefore, a genetic classification of the mitochondrial diseases distinguishes disorders due to mutations in mtDNA, which are governed by the relatively lax rules of mitochondrial genetics, and disorders due to mutations in nDNA, which are governed by the stricter rules of mendelian genetics. Mutations in mtDNA can be divided into those that impair mitochondrial protein synthesis in toto and those that affect any one of the 13 respiratory chain subunits encoded by mtDNA. Essential clinical features for each group of diseases are reviewed. Disorders due to mutations in nDNA are more abundant not only because most respiratory chain subunits are nucleus-encoded but also because correct assembly and functioning of the respiratory chain require numerous steps, all of which are under the control of nDNA. These steps (and related diseases) include: (i) synthesis of assembly proteins; (ii) intergenomic signaling; (iii) mitochondrial importation of nDNA-encoded proteins; (iv) synthesis of inner mitochondrial membrane phospholipids; (v) mitochondrial motility and fission.
DiMauro
Salvatore
S
Department of Neurology, 4-420 College of Physicians and Surgeons, Columbia University, 630 West 168th Street, New York, NY 10032, USA. sd12@columbia.edu
D004272:DNA, Mitochondrial / Q000235:genetics*; D004579:Electron Transport / Q000235:genetics; D015321:Gene Rearrangement; D015894:Genome, Human; D006801:Humans; D017241:MELAS Syndrome / Q000235:genetics; D017243:MERRF Syndrome / Q000235:genetics; D028361:Mitochondrial Diseases / Q000145:classification* / Q000235:genetics / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000235:genetics; D009154:Mutation; D010641:Phenotype; D017354:Point Mutation; D012174:Retinitis Pigmentosa / Q000235:genetics
D004272:DNA, Mitochondrial; D024101:Mitochondrial Proteins