A Novel BLNK Gene Mutation in a Four-Year-Old Child Who Presented with Late Onset of Severe Infections and High IgM Levels and Diagnosed and Followed as X-Linked Agammaglobulinemia for Two Years.

ABSTRACT: Agammaglobulinemia is a rare inherited immunodeficiency disorder. Mutations in the BLNK gene cause low levels of mature B lymphocytes in the peripheral blood leading to recurrent infections. We present a four-year-old Turkish boy who had recurrent respiratory tract infections in the last six months. He had very low IgG (81 mg/dl) and IgA levels (<5 mg/dl) with high IgM (258 mg/dl). Flow cytometric analysis of lymphocyte subsets showed low CD19+ B cells (0.05%). Homozygous c.790C > T (p.Gln264Ter) mutation was detected in the BLNK gene with Targeted Next Generation Sequencing (TNGS) gene analysis. Agammaglobulinemia may be due to different genetic etiologies together with complex genetic events. Although the first diagnosis to be considered in male patients is Bruton's agammaglobulinemia, p

SUBMITTER: Topyildiz E 

PROVIDER: S-EPMC9205732 | biostudies-literature | 2022

REPOSITORIES: biostudies-literature