High prevalence of epilepsy in HAE with normal C1-INH

Dear Editor, Hereditary angioedema (HAE) is characterized by recurrent episodes of subcutaneous or submucosal edema, gastrointestinal attacks, and upper airway edema including laryngeal obstruction. Three types of HAE are currently recognized and genetically identifiable: HAE due to C1 inhibitor (C1-INH) deficiency (C1-INH-HAE-1), characterized by low level of functional C1-INH; HAE due to C1-INH dysfunction (C1-INH-HAE-2), characterized by normal amount but low functional C1-INH levels and caused by SERPING1 mutations, leading to C1-INH deficiency. HAE with normal C1-INH levels (HAE nC1-INH) encompasses diverse diseases and is an uncommon HAE type. HAE nC1-INH has been associated with mutations in several genes, including those for Factor XII (FXII), angiopoietin-1 gene (ANGPT1), plasminogen (PLG) and kininogen-1 (KNG-1). However, in most cases, the underlying genetic mutation is unknown (HAE nC1-INH-unknown).