HLA class I deficiency, also named type I Bare lymphocyte syndrome (BLS), is revealed when HLA class I molecules on lymphocytes cannot be typed by serological techniques due to a low expression of HLA class I molecules on the plasma membrane. This syndrome is caused by any of several defects that result in the lack of cell surface expression of MHC class I or class I and II. It affects both maturation of T cells in the thymus and peripheral immune reactions. The number of well-documented cases of HLA class I molecule deficiencies with normal expression of class II molecules is low.
Alternative names
HLA class I deficiency
Bare lymphocyte syndrome (BLS) type I
Classification
- Combined B and T cell immunodeficiencies
- Major histocompatibility complex class I deficiency
Inheritance
Autosomal recessive
Cross references
Genetically related immunodeficiencies
IDR factfile for CIITA, MHCII transactivating protein deficiency
IDR factfile for RFX-5,MHCII promoter X box regulatory factor 5 deficiency
IDR factfile for RFXAP, Regulatory factor X-associated protein deficiency
Incidence
Incidence is not known.