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Start free with EleplanIsolated succinate-CoQ reductase deficiency
ORPHA:3208Disease
Also called Isolated mitochondrial respiratory chain complex II deficiency · Isolated succinate dehydrogenase deficiency · Isolated succinate-coenzyme Q reductase deficiency · Isolated succinate-ubiquinone reductase deficiency
What it is
A rare, mitochondrial oxidative phosphorylation disorder characterized by a highly variable phenotype. The severe, multisystemic disease involves brain, heart, muscles, liver, kidneys, and eyes and results in death in infancy. Mildly affected individuals have only isolated cardiac or muscle involvement in the adulthood. Histochemical and biochemical analysis reveals a global reduction of succinate dehydrogenase activity.
Key facts
- Prevalence
- <1 / 1 000 000
- Age of onset
- Infancy, 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%
24- Abnormality of the cardiovascular system
- Abnormality of the eye
- Abnormal left ventricular function
- Babinski sign
- Developmental regression
- Distal amyotrophy
- Easy fatigability
- Generalized muscle weakness
- Generalized myoclonic seizure
- Hyperactive deep tendon reflexes
- Hyperactive patellar reflex
- Hyperreflexia in upper limbs
- Hypertrophic cardiomyopathy
- Left ventricular hypertrophy
- Motor delay
- Motor deterioration
- Progressive psychomotor deterioration
- Proportionate short stature
- Proximal muscle weakness
- Reduced visual acuity
- Severe short stature
- Skeletal myopathy
- Spasticity
- Weight loss
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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