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Start free with EleplanUnilateral polymicrogyria
ORPHA:268943Morphological anomaly
What it is
Unilateral polymicrogyria is a cerebral cortical malformation characterized by unilateral excessive cortical folding and abnormal cortical layering. It comprises two sub-types depending on the areas affected: unilateral hemispheric and focal polymicrogyria.
Key facts
- Age of onset
- Infancy, Neonatal
- Classified as
- Morphological anomaly
Recorded for the broader condition
- Inheritance
- Autosomal dominant, Autosomal recessive, Not applicable, X-linked dominantPolymicrogyria
Orphanet records these for the broader condition rather than for this specific form. They are a starting point, not a figure for this subtype — subtypes often differ, and some are defined by being rarer than the condition they sit under.
Signs and symptoms
Common30–79%
8Sometimes5–29%
25- Abnormal facial shape
- Abnormal posturing
- Apnea
- Appendicular hypotonia
- Axial hypotonia
- Cyanosis
- Delayed speech and language development
- Epistaxis
and 17 more in this range
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.
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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