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Start free with EleplanPrimary hypereosinophilic syndrome
ORPHA:314950Disease
Also called Clonal hypereosinophilic syndrome · HES-M · HES-N · Neoplastic hypereosinophilic syndrome · Primary HES
What it is
A rare hypereosinophilic syndrome characterized by hypereosinophilia produced by clonal eosinophils derived from neoplastic stem cells in the absence of any secondary cause of eosinophilia and persisting for at least six months. The condition is associated with signs of organ infiltration, dysfunction, and damage. Clinical manifestations are highly variable, depending on the organ systems involved, and include dermatologic, pulmonary, cardiac, gastrointestinal, and cerebral manifestations, among others.
Key facts
- Age of onset
- All ages
- Classified as
- Disease
Recorded for the broader condition
- Prevalence
- 1-9 / 100 000 (United States)Hypereosinophilic syndrome
- Inheritance
- Not applicable, UnknownHypereosinophilic syndrome
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.
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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