Rare diseases · Sign or symptom
Reduced MHC II cell surface expression
HP:0031390
What it means
Expression of major histocompatibility complex class II molecules at the cell surface is below the lower limit of normal.
Rare diseases that can present with this1
The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.
Part of the broader category
Also called: Abnormal HLA class II surface expression · Reduced human leukocyte antigen class II surface expression
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Start free with EleplanThis page uses the Human Phenotype Ontology (2026-06-23) — Human Phenotype Ontology Consortium, hpo.jax.org. Disease associations from Orphanet (INSERM), CC BY 4.0. Content is educational and is not medical advice.