Mitochondrial encephalopathy, MELAS
- Mitochondrial encephalopathy, MELAS
- MELAS is the acronym for Mitochondrial Encephalopathy, Lactic Acidosis, and Stroke-like episodes. MELAS is a form of dementia. It is caused by mutations in the genetic material (DNA) in the mitochondria. While most of our DNA is in the chromosomes in the cell nucleus, another important cell structure that carries DNA is the mitochondrion. Much of the DNA within the mitochondrion is used to manufacture proteins that help in the mitochondrion's energy-producing function. As a result of the disturbed function of their cells' mitochondria, patients with MELAS develop brain dysfunction (encephalopathy) with seizures and headaches, as well as muscle disease with a buildup of lactic acid in the blood (lactic acidosis), temporary local paralysis (strokelike episodes), and abnormal thinking (dementia). MELAS is diagnosed by muscle biopsy showing characteristic ragged red fibers. Brain biopsy shows stroke-like changes. MELAS affects persons at different times of life, from 4 to 40s. Most patients show symptoms before 20 years old. Patients are managed according to which areas of the body are affected at a particular time. There is no known treatment for MELAS which is progressive and fatal. Mutations (changes) in the mitochondrial chromosome are responsible for a number of disorders including not only MELAS but also for examples: An eye disease called Leber's hereditary optic atrophy; and A type of epilepsy called MERRF which stands for Myoclonus Epilepsy with Ragged Red Fibers. The mitochondria, as mentioned, are normal structures located outside the nucleus in the cell's cytoplasm. Each mitochondrion has a chromosome made of DNA that is quite different from the better known chromosomes in the nucleus. The mitochondrial chromosome is much smaller; it is round (whereas the chromosomes in the nucleus are normally shaped like rods); there are many copies of the mitochondrial chromosome in every cell; and no matter whether we are male or female, we inherit our mitochondrial chromosome from our mother. MELAS and all other mitochondrial diseases were entirely enigmatic before it was discovered that they were due to mutations not in regular chromosomes but in the chromosome of mitochondria.
Medical dictionary.
2011.
Look at other dictionaries:
MELAS syndrome — Mitochondrial myopathy, encephalomyopathy, lactic acidosis, and stroke like episodes Classification and external resources Basal ganglia calcification, cerebellar atrophy, increased … Wikipedia
MELAS syndrome — MELAS is the acronym for Mitochondrial Encephalopathy, Lactic Acidosis, and Stroke like episodes. MELAS is a rare form of dementia. It is caused by mutations in the genetic material (DNA) in the mitochondria. While most of our DNA is in the… … Medical dictionary
Encephalopathy, mitochondrial (MELAS) — MELAS is the acronym for Mitochondrial Encephalopathy, Lactic Acidosis, and Strokelike episodes. MELAS is a form of dementia. It is caused by mutations in the genetic material (DNA) in the mitochondria. While most of our DNA is in the chromosomes … Medical dictionary
Mitochondrial disease — Classification and external resources Micrograph showing ragged red fibres, a finding seen in mitochondrial diseases. Muscle biopsy. Gomori trichrome stain … Wikipedia
Encephalopathy — Classification and external resources ICD 9 348.30 MeSH D001927 Encephalopathy /ɛnˌsɛfəˈlɒpəθi/ means disorder or disease … Wikipedia
Mitochondrial neurogastrointestinal encephalopathy syndrome — Classification and external resources ICD 9 277.87 OMIM 603041 … Wikipedia
MELAS — mitochondrial encephalopathy lactic acidosis and stroke like episodes: a rare metabolic disorder, usually inherited from the mother, that results in short stature and high levels of lactic acid in the blood (see lactic acidosis). Affected… … The new mediacal dictionary
MELAS — Acronym for mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes. One of the mitochondrial disorders, this condition is usually hereditary, with a mutation at the mitochondrial genome at locus 3243. An acronym for… … Medical dictionary
Mitochondrial disease — Mutations (changes) in the mitochondrial chromosome are responsible for a number of disorders including, for example: An eye disease called Leber s hereditary optic atrophy; A type of epilepsy called MERRF which stands for Myoclonus Epilepsy with … Medical dictionary
Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes — Infobox Disease Name = Mitochondrial encephalomyopathy, lactic acidosis, and stroke like episodes Caption = DiseasesDB = 8254 ICD10 = ICD9 = ICDO = OMIM = 540000 MedlinePlus = eMedicineSubj = ped eMedicineTopic = 1406 MeshID = D017241… … Wikipedia
