Mitochondrial diseases (disorders of mitochondrial oxidative phosphorylation) can due to mitochondrial or nuclear DNA abnormalities (e., Deletions, duplications, mutations). Prone to malfunction due to mitochondrial anomalies are particularly tissue with high energy expenditure (eg. As muscles, heart, brain). Certain mitochondrial DNA abnormalities result in characteristic manifestations (s. Some Mitochondrial diseases). Mitochondrial diseases occur with equal frequency in men and women.

Each cell has hundreds of mitochondria in the cytoplasm. Mitochondria contain DNA which encodes 13 proteins, different ribonucleic acids (RNA) and several Regulator / control enzymes in a single ring chromosome. Over 90% of mitochondrial proteins, however, are encoded by genes in the cell nucleus. For practical purposes, all mitochondria from the cytoplasm of the egg are inherited. In this way, mitochondrial DNA comes exclusively from the mother. Mitochondrial diseases (disorders of mitochondrial oxidative phosphorylation) can due to mitochondrial or nuclear DNA abnormalities (e., Deletions, duplications, mutations). Prone to malfunction due to mitochondrial anomalies are particularly tissue with high energy expenditure (eg. As muscles, heart, brain). Certain mitochondrial DNA abnormalities result in characteristic manifestations (s. Some Mitochondrial diseases). Mitochondrial diseases occur with equal frequency in men and women. Mitochondrial abnormalities occur frequently even in more common disorders such as certain forms of Parkinson’s disease (with larger mitochondrial deletions in the Basalganglienzellen) and various muscle diseases. Some Mitochondrial disease Disease description Chronic progressive external ophthalmoplegia Progressive paralysis of the eye muscles usually with a previous bilateral, symmetrical, progressive ptosis that months to years earlier Kearns-Sayre syndrome begins a multisystem variant of chronic progressive external ophthalmoplegia, also arrhythmia, retinitis pigmentosa and CNS degeneration including hereditary optic neuropathy liver Variable, but often devastating bilateral visual loss that often occurs in adolescents and a point mutation in mitochondrial DNA underlies MERRF syndrome myoclonic epilepsy with “ragged red fibers”, dementia, ataxia, and myopathy MELAS syndrome Mitochondrial encephalopathy with lactic acidosis and stroke-like Episodes (MELAS syndrome) Pearson syndrome sideroblastic anemia, pancreatic insufficiency and progressive liver disease that begins in the first months of life and often fatal in infants ends A typical feature of mitochondrial DNA abnormalities is the maternal inheritance. To follow all the offspring of an affected woman have an increased risk of inheriting the anomaly while there is no increased risk to the offspring of a man affected. Variability in clinical manifestations is the rule, and these abnormalities mimic a wide range of diseases that often make the diagnosis very difficult. The variability could be due in part to different mixing ratios of the inherited mutant and normal mitochondrial genomes (heteroplasmy) are present in cells and tissues. Important points Mitochondrial diseases have maternal inheritance pattern. Because the clinical manifestations can be subtle and variable, the diagnosis can be very difficult.

Health Life Media Team

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