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ORPHA:550Disease
Also called Mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes · Mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes · Mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes
What it is
A rare neurometabolic genetic disorder which is progressive and multisystemic due to mitochondrial dysfunction and that is characterized by encephalomyopathy, lactic acidosis, and stroke-like episodes.
Key facts
- Prevalence
- 1-9 / 1 000 000 (Europe)
- Age of onset
- Adolescent, Adult, Childhood
- Inheritance
- Mitochondrial inheritance, Not applicable
- Classified as
- Disease
Prevalence figures describe populations, not individuals, and are often estimates from a single study. Where the figure is an incidence or a birth prevalence, it says so.
Signs and symptoms
Very common80–99%
13Common30–79%
26- Anxiety
- Ataxia
- Basal ganglia calcification
- Bilateral tonic-clonic seizure
- Depression
- Diabetes mellitus
- Encephalopathy
- Fluctuations in consciousness
- Focal-onset seizure
- Gait disturbance
- Hemiparesis
- Impaired visuospatial constructive cognition
- Increased CSF lactate
- Increased CSF protein concentration
- Memory impairment
- Myoclonus
- Myopathy
- Peripheral neuropathy
- Psychosis
- Recurrent paroxysmal headache
- Sensorineural hearing impairment
- Short attention span
- Short stature
- Specific learning disability
- Visual loss
- Vomiting
These ranges are how often a sign appears across everyone diagnosed, not a prediction for one person — most people have some of these and not others. Orphanet also records findings that are specifically absent in this disease; those are in the data but not listed here.
Genes
ICD-10 codes
ICD-10 has no distinct code for most rare diseases, so many are filed under the nearest available one. A shared code identifies the group, not this disease — the ORPHAcode above is what identifies it.
Related health topics
Reached through the ICD-10 categories this disease is filed under, so these describe the broader group rather than this disease specifically.
Benefit programs to look at
Programs whose eligibility touches the same ICD-10 categories. Eligibility is decided by the administering agency, never by this page.
Cross-references
Orphadata Science: Free access data from Orphanet. © INSERM 1999. Data version 2026-06-23. Available under CC BY 4.0. This is a reference, not medical advice.
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