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Start free with EleplanNeurodegeneration due to 3-hydroxyisobutyryl-CoA hydrolase deficiency
ORPHA:88639Disease
Also called HIBCH deficiency · Methacrylic aciduria · Valine metabolic defect
What it is
Neurodegeneration due to 3-hydroxyisobutyryl-CoA hydrolase deficiency is characterised by delayed motor development, hypotonia and progressive neurodegeneration. To date, it has been described in four boys. The syndrome is caused by mutations affecting the two alleles of the HIBCH gene, encoding 3-hydroxyisobutyryl-CoA hydrolase. The mode of transmission has not yet been established.
Key facts
- Prevalence
- <1 / 1 000 000
- Age of onset
- Infancy
- 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%
18- Abnormality of mitochondrial metabolism
- Abnormal vertebral morphology
- Aplasia/Hypoplasia of the corpus callosum
- Epicanthus
- Facial shape deformation
- Failure to thrive
- Feeding difficulties
- Hyperreflexia
- Hypsarrhythmia
- Increased circulating lactate concentration
- Infantile spasms
- Metabolic acidosis
- Nystagmus
- Seizure
- Sleep abnormality
- Strabismus
- Truncal ataxia
- Ventriculomegaly
Sometimes5–29%
6These 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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