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Start free with EleplanMultiple mitochondrial dysfunctions syndrome type 1
ORPHA:401869Disease
Also called MMDS1 · NFU1 deficiency
What it is
A rare mitochondrial disease characterized by failure to thrive, infantile encephalopathy, muscular hypotonia, global developmental delay and regression, pulmonary arterial hypertension, episodes of apnea and bradycardia, respiratory failure, hyperglycinemia, and lactic acidosis. Hypertrophic or dilated cardiomyopathy have also been reported. Brain imaging may show leukoencephalopathy involving variable regions. The disease is typically fatal in early infancy.
Key facts
- Prevalence
- <1 / 1 000 000
- Age of onset
- Neonatal
- Inheritance
- Autosomal recessive
- 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
Common30–79%
11- Decreased activity of mitochondrial respiratory chain
- Decreased activity of the pyruvate dehydrogenase complex
- Developmental regression
- Encephalopathy
- Failure to thrive in infancy
- Feeding difficulties in infancy
- Global developmental delay
- Hyperglycinemia
- Hypotonia
- Increased circulating lactate concentration
- Pulmonary arterial hypertension
Sometimes5–29%
13- Apneic episodes in infancy
- Appendicular spasticity
- Bradycardia
- Cardiomyopathy
- Glutaric aciduria
- Hyperglycinuria
- Hypertonia
- Increased CSF glycine concentration
and 5 more in this range
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.
Gene
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.
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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