Immunodeficiency by defective expression…

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Immunodeficiency by defective expression of MHC class II

ORPHA:572Disease

Also called Bare lymphocyte syndrome type 2 · MHC class II deficiency

What it is

A rare autosomal recessive 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 failure to thrive, and autoimmune disease, and is frequently fatal in childhood.

Key facts

Prevalence
<1 / 1 000 000
Age of onset
Infancy, Neonatal
Inheritance
Autosomal recessive
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

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

CIITADisease-causing germline mutation(s)
RFX5Disease-causing germline mutation(s)
RFXANKDisease-causing germline mutation(s)
RFXAPDisease-causing germline mutation(s)

ICD-10 codes

D81.7ICD-10 names this disease exactly

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

GARD 824MESH C537079MONDO 0008855OMIM 209920UMLS C2931418

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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