Case Report: A novel CIITA mutation causing MHC class II deficiency: first reported case in Morocco.

ABSTRACT: Major histocompatibility complex class II (MHC II) deficiency (bare lymphocyte syndrome type II) is an autosomal-recessive combined immunodeficiency caused by pathogenic variants in the transcriptional regulators CIITA, RFXANK, RFX5, or RFXAP. While RFXANK founder mutations predominate in North Africa, CIITA-related disease is extremely rare. We report two siblings from a consanguineous Moroccan family with the classic early-infancy phenotype. The elder sister developed recurrent febrile rashes, oral candidiasis, and locoregional BCGitis with acid-fast bacilli in granulomas, followed by progressive respiratory failure and fatal cytomegalovirus pneumonitis despite antiviral therapy; immunology showed profound CD4⁺ lymphopenia with CD4/CD8 inversion, near-absent HLA-DR on B cells,

SUBMITTER: Kattra AB 

PROVIDER: S-EPMC12685675 | biostudies-literature | 2025

REPOSITORIES: biostudies-literature