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Mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) is one of many mitochondrial disorders. As mitochondria, which have their own DNA, are exclusively passed on from the mother, these disorders are only maternally inherited.
On imaging, it manifests as multifocal stroke-like cortical lesions in different stages of evolution ("shifting spread" pattern), crossing the cerebral vascular territories, and showing a certain predilection to the posterior parietal and occipital lobes. MR spectroscopy may demonstrate elevated lactate in an otherwise normal appearing brain3.
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As the name suggests, MELAS is characterized by 'stroke-like' episodes, typically in childhood or early adulthood (90% present before 40 years of age).
MELAS usually has a relapsing-remitting course, with or without superimposed accretion of permanent deficits. Clinical presentation is highly variable between patients (even from the same affected family), with potential clinical features including 1,6,7:
The defect involves the respiratory chain, which is responsible for energy production 7. A point mutation at mtDNA nucleotide (A to G translocation) wh
What to know about MELAS syndrome
Mitochondrial encephalopathy with lactic acidosis and stroke-like episodes (MELAS) syndrome is a genetic condition that affects the nervous system and muscles, typically in children.
MELAS syndrome is a genetic condition that affects the activity of mitochondria of cells in the body. Mitochondria help vända food into energy, which allows cells to function as usual. Due to issues with mitochondria, MELAS syndrome disrupts this process and causes a range of symptoms, typically in the nervous system.
The United Mitochondrial Disease Foundation suggests that around 1–16 out of , adults have MELAS syndrome. However, the disease typically begins during childhood, and symptoms may sometimes develop before 2 years old. The symptoms progressively worsen over time and typically become fatal.
MELAS syndrome causes early symptoms that include seizures and headaches. It may lead to stroke-like episodes, as well as motor and intellectual disabilities. There is currently no cure for MELAS syndrome, but doctors can manage some symptoms of the condition using a combination of treatments.
This article discusses the causes and symptoms of MELAS sy
MELAS syndrome
Mitochondrial disease
Medical condition
| Mitochondrial myopathy, encephalomyopathy, lactic acidosis, and stroke-like episodes | |
|---|---|
| Basal ganglia calcification, cerebellar atrophy, increased lactate; a CT image of a person diagnosed with MELAS | |
| Specialty | Neurology&#; |
| Frequency | 1 in [1] |
MELAS (Mitochondrial Encephalopathy, Lactic Acidosis, and Stroke-like episodes) is one of the family of mitochondrial diseases, which also include MIDD (maternally inherited diabetes and deafness), MERRF syndrome, and Leber's hereditary optic neuropathy. It was first characterized under this name in [2] A feature of these diseases is that they are caused by defects in the mitochondrial genome which is inherited purely from the female parent.[3] The most common MELAS mutation is mitochondrial mutation, mtDNA, referred to as mA>G.
Signs and symptoms
[edit]MELAS is a condition that affects many of the body's systems, particularly the brain and nervous system (encephalo-) and muscles (myopathy). In most cases, the signs and symptoms of this disorder appear in childhood following a period of normal development.[4