Abstract
Hereditary angioedema with normal C1 esterase inhibitor is a rare genetic disorder characterized by periodical and unpredictable angioedema without quantitative and qualitative deficiency of C1-inhibitor. According to the modern classification, this disease can present as two different endotypes: bradykinin-mediated and endothelium dysfunction-associated. Diagnosis of this disease is complicated by the need to perform genetic screening because available laboratory tests (C1-inhibitor, its functionality, and C4 protein in blood plasma) are within normal values, functional molecular tests are not available, clinical data are limited to few cohorts and, for some genetic defects, to single clinical observations. Genetic examination of patients with recurrent angioedema expands the cohort of patients with hereditary angioedema and normal C1 esterase inhibitor. The article describes 17 patients with hereditary angioedema with normal C1 esterase inhibitor who underwent treatment at a specialized center in Moscow. The bradykinin-mediated angioedema endotype was found in 13 patients (9 with mutation in PLG, 2 with mutation in FXII, and 2 with mutation in KNG1), and endothelium dysfunction-associated angioedema was diagnosed in 4 patients with mutation in MYOF (2 asymptomatic carriers). Currently, data on the clinical presentation, diagnosis, and therapy of patients are limited to single clinical cases and small clinical case series, thus further data collection is needed. The publication contains unique data on the algorithm of diagnosis and selection of therapy in patients with angioedema and normal C1-inhibitor level.