Rare diseases · Sign or symptom
Delayed myelination
HP:0012448
What it means
Delayed myelination.
Rare diseases that can present with this61
Common30–79%
21- 3-phosphoglycerate dehydrogenase deficiency, infantile/juvenile form
- Allan-Herndon-Dudley syndrome
- Angelman syndrome due to maternal 15q11q13 deletion
- Combined oxidative phosphorylation defect type 13
- DPM1-CDG
- Folinic acid-responsive seizures
- FOXG1 syndrome
- Houge-Janssens syndrome type 2
- Microcephaly-facial dysmorphism-ocular anomalies-multiple congenital anomalies syndrome
- Microcephaly-thin corpus callosum-intellectual disability syndrome
- Multiple congenital anomalies-hypotonia-seizures syndrome
- PLAA-associated neurodevelopmental disorder
- PMM2-CDG
- PRUNE1-related neurological syndrome
- S-adenosylhomocysteine hydrolase deficiency
- SATB2-associated syndrome due to a pathogenic variant
- Severe intellectual disability-poor language-strabismus-grimacing face-long fingers syndrome
- Severe neonatal hypotonia-seizures-encephalopathy syndrome due to 5q31.3 microdeletion
- SLC35A2-CDG
- WARS2-related combined oxidative phosphorylation defect
- X-linked intellectual disability-limb spasticity-retinal dystrophy-arginine vasopressin deficiency
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
Delayed myelination
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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.