Rare diseases · Sign or symptom
CNS hypomyelination
HP:0003429
What it means
Reduced amount of myelin in the central nervous system resulting from defective myelinogenesis.
Rare diseases that can present with this18
Very common80–99%
6Common30–79%
8- DYRK1A-related intellectual disability syndrome due to 21q22.13q22.2 microdeletion
- Juvenile amyotrophic lateral sclerosis
- NKX6-2-related autosomal recessive hypomyelinating leukodystrophy
- PYCR2-related microcephaly-progressive leukoencephalopathy
- S-adenosylhomocysteine hydrolase deficiency
- Sandhoff disease, infantile form
- Tremor-ataxia-central hypomyelination syndrome
- Wiedemann-Rautenstrauch syndrome
The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.
Part of the broader category
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Start free with EleplanThis page uses the Human Phenotype Ontology (2026-06-23) — Human Phenotype Ontology Consortium, hpo.jax.org. Disease associations from Orphanet (INSERM), CC BY 4.0. Content is educational and is not medical advice.