bare lymphocyte syndrome
bare lym·pho·cyte syn·drome
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.