Assessing whole-exome sequencing data from undiagnosed Brazilian patients to improve the diagnostic yield of inborn errors of immunity.

Objectives: Inborn error of immunity (IEI) comprises a broad group of inherited immunological disorders that usually display an overlap in many clinical manifestations challenging their diagnosis. The identification of disease-causing variants from whole-exome sequencing (WES) data comprises the gold-standard approach to ascertain IEI diagnosis. The efforts to increase the availability of clinically relevant genomic data for these disorders constitute an important improvement in the study of rare genetic disorders.

Clinical and genetic findings in two siblings with X-Linked agammaglobulinemia and bronchiolitis obliterans: a case report.

Background: X-linked agammaglobulinemia (XLA) is an Inborn Errors of Immunity (IEI) characterized by pan-hypogammaglobulinemia and low numbers of B lymphocytes due to mutations in BTK gene. Usually, XLA patients are not susceptible to respiratory tract infections by viruses and do not present interstitial lung disease (ILD) such as bronchiolitis obliterans (BO) as a consequence of acute or chronic bacterial infections of the respiratory tract. Although many pathogenic variants have already been described in XLA, the heterogeneous clinical presentations in affected patients suggest a more complex genetic landscape underlying this disorder.