Disease Directory Erdheim-Chester Disease
Neurological

Erdheim-Chester Disease

Also known as: ECD, non-Langerhans cell histiocytosis, polyostotic sclerosing histiocytosis, BRAF-mutant histiocytosis

Prevalence

1-9 per 1,000,000 (Orphanet)

Onset

Adult

Type

Somatic clonal mutation (neoplastic, MAP kinase pathway)

Gene

BRAF (V600E in ~57%), MAP2K1, NRAS, PIK3CA

About Erdheim-Chester Disease

Erdheim-Chester disease (ECD) is a rare non-Langerhans histiocytosis in which clonal histiocytes infiltrate multiple organs. The majority of patients carry the BRAF V600E somatic mutation. Common manifestations include bilateral symmetric osteosclerosis of long bones, retroperitoneal fibrosis, periaortic sheathing, cardiac involvement, and CNS involvement (diabetes insipidus, cerebellar ataxia, exophthalmos). Vemurafenib (Zelboraf) and cobimetinib are approved/used off-label for BRAF-mutant ECD.

Common Clinical Features

Bone pain (long bone osteosclerosis) Diabetes insipidus Exophthalmos Cerebellar ataxia Retroperitoneal fibrosis Periaortic infiltration Skin xanthomas

Clinical Trial Eligibility Tips

What to know before applying to Erdheim-Chester Disease trials.

BRAF V600E mutation testing on tissue biopsy (bone marrow, lesion) is required for BRAF inhibitor trial eligibility

For BRAF-wild-type ECD, MAPK pathway mutation analysis (MAP2K1, ARAF, NRAS) should be performed — alternative targeted therapies exist

Whole-body FDG-PET/CT and MRI are standard staging and monitoring tools required at baseline

Prior BRAF inhibitor therapy history and duration of response must be documented for resistance and combination therapy trials

Patient Resources

Patient Organization

Erdheim-Chester Disease Global Alliance

Visit website ↗

Natural History Registry

ECD Global Alliance Patient Registry

Join registry ↗

Orphanet

European reference resource for rare diseases (ORPHA:35687)

View on Orphanet ↗

NORD

National Organization for Rare Disorders

Search NORD ↗

Find recruiting Erdheim-Chester Disease trials

Search 500,000+ studies from ClinicalTrials.gov, filtered for Erdheim-Chester Disease. Updated daily.

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