The<unk> , type II <unk>  II) is a rare recessive genetic condition in which a group of genes called major histocompatibility complex class II (MHC class II) are not expressed. The result is that the immune system is severely compromised and cannot effectively fight infection. Clinically, this is similar to severe combined immunodeficiency (SCID), in which<unk>  precursor cells are improperly formed. As a notable contrast, however,<unk>  does not result in decreased B- and T-cell counts, as the development of these cells is not impaired. TAP (transporter associated with antigen presentation) deficiency syndrome is the best characterized of<unk>  I. Symptoms can include recurrent bacterial infections of the respiratory tract and chronic skin lesions. Bronchiectasis and respiratory failure and complete destruction of the nose and cerebral abscess are severe complications. Diarrhea can be among the associated conditions.
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