bare lymphocyte syndrome


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bare lym·pho·cyte syn·drome

absence of HLA antigens on peripheral mononuclear cells, which may result in immunodeficiency.

bare lymphocyte syndrome

an immune deficiency condition caused by defective beta-2 microglobulin, one of the major histocompatibility antigens on cell surfaces. It is inherited as an autosomal-recessive trait. The deficiency causes a severe combined immunodeficiency resulting from the lack of antigen presentation by type I and/or type II major histocompatibility complex.

bare lymphocyte syndrome

An autosomal recessive form of severe combined immunodeficiency (OMIM:209920), which is described in several North African kindreds. It results from non-expression of HLA-A, -B or -C (Class-I MHC), related to a defect in surface expression of beta2-microglobulin; in some patients, HLA-Dr is also not expressed.

Clinical findings
Variable: from asymptomatic to mucocutaneous candidiasis, respiratory tract infections, opportunistic infections, chronic diarrhoea, malabsorption, poor response to antigens, aplastic anaemia, and leukopaenia with normal/increased B cells and decreased T cells.
 
Molecular pathology
Possibly due to a defect in gene activation and/or a defect in accessibility of the promoter protein; mutations in any of four genes can cause the BSL:
• Class-II trans-activator (CIITA);
• Regulatory factor of the X box 5 (RFX5)
• RFX-associated protein (RFXAP);
• RFX ankyrin repeats (RFXANK).

Management
Bone marrow transplantation.

bare lymph·o·cyte syn·drome

(bār lim'fŏ-sīt sin' drōm)
Absence of human leukocyte antigens on peripheral mononuclear cells, which may result in immunodeficiency.

bare lymphocyte syndrome

A rare autosomal recessive immunodeficiency genetic disorder that results in the absence of the class 2 MAJOR HISTOCOMPATIBILITY COMPLEX glycoprotein molecules. Children with this mutation are extremely susceptible to infection with all kinds of organisms and seldom survive for more than four years from birth.