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Start free with EleplanFatty acid hydroxylase-associated neurodegeneration
ORPHA:329308Disease
Also called FAHN
What it is
Fatty acid hydroxylase-associated neurodegeneration (FAHN) is a very rare, autosomal recessive form of neurodegeneration with brain iron accumulation (NBIA) characterized by childhood-onset focal dystonia, progressive spastic paraplegia that progresses to tetra paresis, ataxia, dysarthria, intellectual decline, and oculomotor disturbances (optic atrophy), accompanied by iron deposition in the globus pallidus.
Key facts
- Prevalence
- <1 / 1 000 000
- Age of onset
- Adolescent, Childhood
- 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%
20- Anarthria
- Atrophy of the spinal cord
- Bilateral tonic-clonic seizure
- Cerebellar atrophy
- Cerebellar vermis atrophy
- Color vision test abnormality
- Dysarthria
- Generalized dystonia
- Horizontal nystagmus
- Hypoplasia of the corpus callosum
- Loss of ambulation
- Motor aphasia
- Optic atrophy
- Progressive extrapyramidal movement disorder
- Progressive spastic paraparesis
- Progressive spastic quadriplegia
- Slow decrease in visual acuity
- Supranuclear gaze palsy
- Upper motor neuron dysfunction
- Visual field defect
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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