RecruitingNCT06092346
Immune
Hyper IgM Syndrome
Also known as HIGM, CD40L deficiency, CD40 ligand deficiency
Hyper IgM Syndrome is a group of rare primary immunodeficiencies characterized by elevated or normal serum IgM with markedly reduced or absent IgG, IgA, and IgE, caused by defects in the molecular machinery required for B-cell class-switch
ORPHA:183 ↗Gene CD40LGGene AIDGene UNGPrevalence 1 in 500,000-1,000,000Onset Infancy to early childhoodCombined primary immunodeficiency (class-switch recombination defect)
4
studies recruiting now
as of 7 Sept 2026
41
studies registered in total
as of 7 Sept 2026
1
countries with a recruiting site
as of 7 Sept 2026
16 Dec 2025
most recent study posted
among recruiting studies
Recruiting trials
RecruitingPhase 2NCT07284641
Hematopoietic Stem Cell Transplantation (HSCT) for Common Variable Immunodeficiency (CVID) and Other Autoimmune Manifestations of Primary Immune Regulatory Disorders (PIRD)
RecruitingNCT04528355
Data Collection Study of Patients With Non-Malignant Disorders Undergoing UCBT, BMT or PBSCT With RIC
RecruitingPhase 2NCT01962415
Reduced Intensity Conditioning for Non-Malignant Disorders Undergoing UCBT, BMT or PBSCT
Showing the 4 most recently updated recruiting studies, as recorded 7 Sept 2026. Live status on each study page.
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Countries with at least one recruiting site among the studies above, 7 Sept 2026. Tap a country to search trials there.
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About Hyper IgM Syndrome
Hyper IgM Syndrome is a group of rare primary immunodeficiencies characterized by elevated or normal serum IgM with markedly reduced or absent IgG, IgA, and IgE, caused by defects in the molecular machinery required for B-cell class-switch recombination. The most common form is X-linked, caused by mutations in CD40LG encoding CD40 ligand, and predisposes patients to opportunistic infections including Pneumocystis jirovecii pneumonia and Cryptosporidium cholangiopathy. Hematopoietic stem cell transplantation is the only curative option currently available for CD40L deficiency.
Common clinical features
Recurrent Pneumocystis jirovecii pneumoniaCryptosporidium-associated sclerosing cholangitisNeutropenia (autoimmune or cyclic)Markedly elevated serum IgM with absent IgG/IgA/IgERecurrent oral ulcers and gingivitisSusceptibility to opportunistic fungal and viral infectionsProgressive liver disease from biliary complications
From Orphanet’s phenotype annotations (CC BY 4.0). Not a complete list.
Before you apply
Things trial teams commonly ask about for Hyper IgM Syndrome. Not eligibility rules; those are set by each study.
- Confirm the specific molecular defect (CD40LG, AID, UNG, or other) as gene therapy trials are mutation-specific and not interchangeable across HIGM subtypes
- Active Cryptosporidium infection or established biliary cirrhosis may exclude from transplant conditioning trials — current liver function tests and imaging are essential
- Neutropenia trials may co-enroll HIGM patients; document ANC nadir and G-CSF use history
Related conditions
Information, not medical advice. Trial listings are shown as recorded on ClinicalTrials.gov; whether any study is right for you is a decision for you and your clinicians, and eligibility is decided by each research team. Disease information from Orphanet (CC BY 4.0).