ORPHA:572
Immunodeficiency by defective expression of MHC class II
Also known as: Bare lymphocyte syndrome type 2 · MHC class II deficiency
Query health: suspect — Only one of 2 strategies returned hits (phrase).
Publications
625
Trials
0
Interventional, condition-specific
Researchers
1,573
Distinct authors in sample
Gene link
CIITA, RFX5, RFXANK
Definitive
Readiness
2/6
Stages with a signal
Clinical definition (Orphanet)
A rare primary immunodeficiency characterized by absence of HLA class II molecules on the surface of immune cells, leading to severely impaired cellular and humoral immune response to foreign antigens, severe CD4+ T-cell lymphopenia, and hypogammaglobulinemia. The disease clinically manifests with early onset of severe and recurrent infections mainly of the respiratory and gastrointestinal tract, protracted diarrhea with , and autoimmune disease, and is frequently fatal in childhood.
How rare: <1 / 1 000 000 — fewer than one in a million. In a city the size of Kolkata, that might mean on the order of fifteen people.
Cross-references
Joined from Mondo / Orphanet. MeSH labels may enter searches; UMLS / OMIM / NCIT are stored for reference.
- MONDO:0008855
- MeSH:C537079
- UMLS:C5447452
- NCIT:C176823
- NCIT:C3895
Additional Mondo synonyms (5)
HLA class 2-negative SCID · HLA class 2-negative severe combined immunodeficiency · MHC class II expression deficiency · immunodeficiency by defective expression of HLA class type 2 · major histocompatibility complex class II expression deficiency
Research stages
Trial readiness signals
Where this condition sits on an open-data research pipeline — not how close a treatment is, and not medical advice. Empty stages often mean “not in these databases under this Mondo ID,” not “impossible.”
2/6 stages with a signal
No matched interventional trial; the gene is known and literature exists — preclinical or natural-history work may still be the practical next step.
- Gene identifiedPresent
Definitive — CIITA, RFX5, RFXANK, RFXAP
- LiteraturePresent
625 matched papers (247 in last 10 years) Source
- Phenotype characterisedNot checked
Not yet enriched from Monarch / HPO
- Animal modelNot checked
Not yet enriched from Monarch / Alliance
- Orphan designationNot checked
FDA/EMA orphan-drug designation not enriched yet
- Interventional trialNot found
No matched interventional trial under our ClinicalTrials.gov rules
Biology
Genes and phenotypes
Gene–disease validity from GenCC, plus phenotypes and animal models joined from Monarch Initiative via Mondo ID — not a clinical diagnosis aid.
Do we know what causes it?
Yes — we know a specific gene responsible (CIITA, RFX5, RFXANK…).
GenCC classification: Definitive.
Phenotypes (Monarch / HPO)
Not enriched in this build — Monarch phenotype joins were not run for this record.
Animal models (Monarch / Alliance)
Not enriched in this build.
Literature
Is anyone studying this?
625
625 papers have been published on this condition. That is a real research literature — still far smaller than common diseases (breast cancer: over 700,000 papers). Median papers in the last 10 years for a rare disease in this dataset (publications denominator n=5449) is 41.
625 papers since the earliest indexed year in this search — median last-10-year count for a rare disease in this dataset is 41 (publications denominator n=5449).
247 in the last 10 years · low confidence
Phrase hits: 625 · MeSH hits: 0
Who's working on it?
1,573
Distinct author names in 200 sampled papers — named people below.
Who's working on it?
No interventional trial matched this name; these authors publish on it in the sampled literature — a practical starting point for contact.
- 01Notarangelo LD10 papers · 2026
Division of Immunology, Boston Children's Hospital, and the Departments of Pediatrics and Pathology, Harvard Medical School, Boston, Mass.
Papers in Europe PMC - 02Barbouche MR6 papers · 2018
Laboratory of Immunology, Institut Pasteur de Tunis, Tunisia.
Papers in Europe PMC - 03Mach B6 papers · 2007Papers in Europe PMC
- 04Steimle V6 papers · 2007
Jeantet Laboratory of Molecular Genetics, Department of Genetics and Microbiology, University of Geneva Medical School, Switzerland.
Papers in Europe PMC - 05Bejaoui M5 papers · 2018
Pediatrics Department, Bone Marrow Transplantation Center, Tunis, Tunisia.
Papers in Europe PMC - 06Dalvi A5 papers · 2020
Department of Paediatric Immunology and Leukocyte Biology, National Institute of Iummunohematology (ICMR), Mumbai, India.
Papers in Europe PMC - 07Fischer A5 papers · 2011Papers in Europe PMC
- 08Gupta M5 papers · 2020
Department of Paediatric Immunology and Leukocyte Biology, National Institute of Iummunohematology (ICMR), Mumbai, India.
Papers in Europe PMC - 09Ailal F4 papers · 2025
Unité d'Immunologie Clinique, Service de Pédiatrie 1, CHU Ibn Rochd, Casablanca, Morocco
Papers in Europe PMC - 10Al-Mousa H4 papers · 2023
Section of Pediatric Allergy/Immunology, Department of Pediatrics, King Faisal Specialist Hospital & Research Center, Riyadh, Saudi Arabia.
Papers in Europe PMC
Clinical research
Is a treatment being tested?
0
interventional trials for this specific condition
No interventional trial testing a treatment matched this specific condition name on ClinicalTrials.gov (observational studies and pan-disease registries are listed separately when present).
Data as of 27 July 2026
No matched interventional trials. This is true for 73% of diseases in the trials denominator (5114 of 7003). Here are the researchers publishing on it.
low confidence · 36.5th percentile (trials denominator)
Recruiting interventional trials
From the matched ClinicalTrials.gov set
No interventional trial testing a treatment was found for this specific condition name on ClinicalTrials.gov.
See who's working on it — people publishing on this disease are often the practical next contact when no trial is listed.
Where to find support
We do not yet link condition-specific patient organisations. These umbrella groups support undiagnosed and ultra-rare families:
India — NPRD
Last verified 2026-07-26Likely covered — the policy lists Severe combined immunodeficiency (SCID) as a category (Group 1), and this condition is a form of it. Confirm eligibility with a Centre of Excellence.
Group 1 — one-time curative treatment
Up to ₹50 lakh per patient
Financial support for treatment at notified Centres of Excellence (figures evolved from the original ₹20 lakh Group-1 ceiling).
Policy figures change. Verify current MoHFW / CoE guidance before relying on any amount. Verify
Centres of Excellence (15)
- All India Institute of Medical Sciences (AIIMS) — New Delhi, Delhi
- Maulana Azad Medical College — New Delhi, Delhi
- Sanjay Gandhi Post Graduate Institute of Medical Sciences — Lucknow, Uttar Pradesh
- Post Graduate Institute of Medical Education and Research (PGIMER) — Chandigarh, Chandigarh
- Centre for DNA Fingerprinting & Diagnostics with Nizam’s Institute of Medical Sciences — Hyderabad, Telangana
- King Edward Memorial Hospital — Mumbai, Maharashtra
- Institute of Post-Graduate Medical Education and Research (IPGMER) — Kolkata, West Bengal
- Centre for Human Genetics with Indira Gandhi Hospital — Bengaluru, Karnataka
- Institute of Child Health and Hospital for Children (ICH & HC) — Chennai, Tamil Nadu
- All India Institute of Medical Sciences (AIIMS) — Jodhpur, Rajasthan
- Sree Avittam Thirunal Hospital (SAT), Government Medical College — Thiruvananthapuram, Kerala
- All India Institute of Medical Sciences (AIIMS) — Bhopal, Madhya Pradesh
- Regional Institute of Medical Sciences (RIMS) — Imphal, Manipur
- All India Institute of Medical Sciences (AIIMS) — Patna, Bihar
- Assam Medical College & Hospital — Dibrugarh, Assam
Voluntary contributions / crowdfunding (separate from CoE funding): https://rarediseases.mohfw.gov.in/
Hand-curated for this project. ORPHAcode mappings are best-effort and may be incomplete or imprecise for umbrella categories. Parent (Mondo) matches mean the policy lists a broader category — confirm eligibility with a Centre of Excellence. Financial entitlements summarised from public policy statements and may change. This is not official government guidance.
How we counted this
Europe PMC query (preferred label + any corrected label + Orphanet and Mondo exact synonyms, stoplisted; unioned with resolved MeSH labels when available). UMLS / OMIM / NCIT cross-references are stored on the overview but are not added to the query string.
"Immunodeficiency by defective expression of MHC class II" OR "Immunodeficiency by defective expression of the MHC class II" OR "Bare lymphocyte syndrome type 2" OR "MHC class II deficiency" OR "HLA class 2-negative SCID" OR "HLA class 2-negative severe combined immunodeficiency" OR "MHC class II expression deficiency" OR "immunodeficiency by defective expression of HLA class type 2" OR "immunodeficiency by defective expression of the HLA class type 2" OR "major histocompatibility complex class II expression deficiency"
ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):
"Immunodeficiency by defective expression of MHC class II" OR "Immunodeficiency by defective expression of the MHC class II" OR "Bare lymphocyte syndrome type 2" OR "MHC class II deficiency" OR "HLA class 2-negative SCID" OR "HLA class 2-negative severe combined immunodeficiency" OR "MHC class II expression deficiency" OR "immunodeficiency by defective expression of HLA class type 2" OR "immunodeficiency by defective expression of the HLA class type 2" OR "major histocompatibility complex class II expression deficiency" OR "CIITA" OR "RFX5" OR "RFXANK" OR "RFXAP" OR "familial severe combined immunodeficiency"
Recall-expansion terms: CIITA, RFX5, RFXANK, RFXAP, familial severe combined immunodeficiency
Study-type breakdown: 0 interventional · 0 observational · 0 expanded access. Only interventional studies enter the trial headline.
Query health: suspect — strategies attempted: phrase, recall-expansion; with hits: phrase
Run this search on ClinicalTrials.gov
Confidence reasoning
- Preferred label is multi-word and distinctive
- No synonyms dropped by stoplist
- No label/synonym collisions with other diseases in this corpus
- Publication count (625) is implausibly high for prevalence class "<1 / 1 000 000" — treat as possible over-matching, not a measure of research intensity
Ingested 2026-07-26T14:23:53.787Z