Cohort of Iranian Patients with Congenital Agammaglobulinemia: Mutation Analysis and Novel Gene Defects

Objectives: Impairment in early B-cell development can cause a predominantly antibody deficiency with severe depletion of peripheral B-cells. Mutations in the gene encoding for Bruton's-tyrosine-kinase (BTK) and the components of the pre-B-cell receptor complex or downstream signaling molecules have been related to this defect in patients with agammaglobulinemia. Methods: Iranian patients with congenital agammaglobulinemia were included and the correlation between disease-causing mutations and parameters such as clinical and immunologic phenotypes were evaluated in available patients. Results: Out of 87 patients, a molecular investigation was performed on 51 patients leading to identification of 39 cases with BTK (1 novel mutation), 5 cases of mu-heavy chain (3 novel mutations) and 1 case of Ig alpha-deficiencies. Conclusion: Although there is no comprehensive correlation between type of responsible BTK mutation and severity of clinical phenotype, our data suggest that BTK-deficient and autosomal recessive agammaglobulinemia patients differ significantly regarding clinical/immunologic characteristics.