Molecular characterization of Agammaglobulinemia, X-linked 1: A case-series from Iran

X-linked agammaglobulinemia (XLA) is among the most frequent primary immunodeficiencies in childhood. This disorder is caused by a disruption in B cell development resulted from mutations in Bruton’s tyrosine kinase ( BTK ) gene. We used whole exome sequencing (WES) to find the underlying genetic basis of immunodeficiency in a group of patients with different clinical manifestations and reported 10 cases of XLA. A range of different mutation types, including nonsense (e.g., p.Gln234*), missense (e.g., p.Arg615Ser), and frameshift (e.g., p.Glu271Lysfs*6) mutations, as well as one splice site variant (c.1631 + 5G > T in Case 8) were detected in the patients. This study provides an overview of BTK variants among Iranian patients and shows the heterogeneous pattern of these variants. Based on the importance of early diagnosis and identification of genetic basis of immunodeficiency in the affected individuals, we suggest early application of WES in the course of molecular diagnosis to save time and cost.