<unk>  is a condition caused by mutations in certain genes of the major histocompatibility complex or involved with the processing and presentation of MHC molecules. It is a form of severe combined immunodeficiency.
Bare lymphocyte syndrome
Kasabach–Merritt syndrome
Adult-onset immunodeficiency syndrome
Diffuse infiltrative lymphocytosis syndrome
Mast cell activation syndrome
Pitt–Hopkins syndrome
EAST syndrome
OSLAM syndrome