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ORPHA:296Disease
Also called Enchondromatosis Spranger type I · Multiple Enchondromatosis type I · Multiple Enchondromatosis, Ollier type
What it is
A rare primary bone dysplasia characterized by multiple enchondromas (benign cartilage-forming tumors). The lesions are generally unilateral or asymmetrically distributed. The most common affected site is the appendicular skeleton.
Key facts
- Prevalence
- 1-9 / 100 000 (Europe)
- Age of onset
- Adolescent, Adult, Childhood
- Inheritance
- Not applicable
- 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
Very common80–99%
7Sometimes5–29%
16- Chondrosarcoma
- Cranial nerve paralysis
- Cubitus valgus
- Facial asymmetry
- Genu valgum
- Genu varum
- Lower limb asymmetry
- Lymphangioma
and 8 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.
Genes
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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