Dobbs et al. (2007) reported a 15-year-old female patient of Georgian (South Caucasus) descent living in Austria who had recurrent infections, hypogammaglobulinemia, and less than 2% circulating CD19-positive B cells. The patient had been well until 5 months ... Dobbs et al. (2007) reported a 15-year-old female patient of Georgian (South Caucasus) descent living in Austria who had recurrent infections, hypogammaglobulinemia, and less than 2% circulating CD19-positive B cells. The patient had been well until 5 months of age, when she developed recurrent bronchitis. At 15 months of age, she was evaluated because of persistent cough and pneumonia and was found to have panhypogammaglobulinemia and less than 1% B cells. She was started on intravenous gamma-globulin at that time. At 3 and 10 years of age, she was treated for pneumonia. She was doing well at 15 years of age on subcutaneous gamma-globulin with normal growth and development and no signs of infection. Flow cytometric analysis demonstrated that the patient had a profound deficit in IgM-expressing B cells. Ferrari et al. (2007) reported a 20-year-old Italian man with agammaglobulinemia. He was first hospitalized at age 8 months with pneumonia Salmonella enteritis. Immunologic work-up showed marked hypogammaglobulinemia with low IgG and undetectable IgA and IgM, and absence of peripheral CD19-positive cells. There were normal numbers of T and NK cells, and T-cell function was normal. Despite appropriate immunoglobulin substitution therapy, he continued to have episodes of bacterial conjunctivitis, acute otitis media, sinusitis, and bronchitis.
In a 15-year-old female patient with early onset of infections, hypogammaglobulinemia, and markedly reduced B cells (AGM6), Dobbs et al. (2007) identified a a homozygous mutation (G137S; 147245.0001) in the CD79B gene. The substitution occurred adjacent to the ... In a 15-year-old female patient with early onset of infections, hypogammaglobulinemia, and markedly reduced B cells (AGM6), Dobbs et al. (2007) identified a a homozygous mutation (G137S; 147245.0001) in the CD79B gene. The substitution occurred adjacent to the cysteine required for the disulfide bond between CD79A (112205) and CD79B. Expression of the mutant protein in 293T cells or Jurkat T cells showed that it formed disulfide-linked complexes and brought IGHM (147020) to the cell surface inefficiently. In an Italian patient with agammaglobulinemia-6, Ferrari et al. (2007) identified a homozygous mutation in the CD79B gene (147245.0002).