The Expanding Spectrum of Mutations in Hereditary Angioedema

The evolution in the knowledge of rare genetic diseases such as hereditary angioedema (HAE) has increased at a parallel pace with the development of new molecular tools. The deficiency of C1 inhibitor (C1-INH) has been recognized as the main cause of HAE (HAE-C1-INH) since the 1960s, but the discovery of the wide spectrum of mutations affecting the C1-INH gene (SERPING1) was possible only from the late 1980s, when Sanger sequencing became available and more accessible worldwide. Nevertheless, the involvement of other genes in HAE was discovered only in 2006 with the description of mutations in the F12 gene in patients with HAE and normal C1-INH. In the last 3 years, advanced next-generation sequencing techniques allowed the identification of mutations in 5 new genes being associated with HAE and normal C1-INH: ANGPT1 (angiopoietin-1), PLG (plasminogen), KNG1 (kininogen), MYOF (myoferlin), and HS3ST6 (heparan sulfate-glucosamine 3-O-sulfotransferase 6). The knowledge provided by the new era of genomic studies was pivotal in the discovery of mutations in new genes responsible for this complex pathogenesis. Genomics advances promise a better understanding of unknown mechanisms leading to HAE, the establishment of new molecular targets for novel therapeutic agents, and personalized treatment. (C) 2021 American Academy of Allergy, Asthma & Immunology