Tehran University of Medical Sciences Immunology and Genetics Journal 2645-4831 3 3 2020 09 22 53 58 Fereshte Salami Reproductive Immuology Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran 2020 07 13 Bialelic LRBA mutations leads to an Immune dysregulation disorder which name is LRBA deficiency. A wide spectrum of clinical manifestation associated with recurrent infections, enteropathy, hypogammaglobulinemia, and autoimmune manifestations. LRBA interacts with CTLA-4 within recycling it to the T-cell surface. Accordingly, LRBA deficiency abolish CTLA4 protein expression. In this study, we present a case with homozygous mutation in LRBA gene and normal level of CTLA4 protein. This patient revelaed low immunoglobulin levels, CD4+ cells, and CD19+ cells. https://igj.tums.ac.ir/index.php/igj/article/view/57 https://igj.tums.ac.ir/index.php/igj/article/download/57/48