A Case of X-Linked Agammaglobulinemia with Btk Gene Intron 2 Mutation

X-linked agammaglobulinemia is the most common type of primary immunodeficiency disorder. Mutation of the cytoplasmic tyrosine kinase gene, Btk (Bruton's tyrosine kinase), is known to be the etiology of X-linked agammaglobulinemia. The patients with this disease manifest a B-cell deficiency and low levels of serum immunoglobulin; due to the deficient antibodies, they suffers from recurrent upper and lower respiratory infections. We report here a 24-year-old male with an initial clinical impression of recurrent pneumonia and bronchiectasis. The patient presented with marked pan-hypogammaglobulinemia and the absence of circulating B-lymphocytes on the immunologic study, and he carried a splicing mutation of intron 2 in the Btk gene (IVS2 -3C> G).