2.1 Patients
Patients diagnosed with C1-INH-HAE at the Belarusian Research Center for Pediatric Oncology Hematology and Immunology in Minsk since 2010 have been included in the study. For each patient, the following data were collected from the medical records: date of birth, age at symptoms onset, date of diagnosis, plasma levels of complement parameters. Diagnosis of C1-INH-HAE was based on personal and/or family history of angioedema and on C1-INH functional or antigenic plasma levels ≤50% of normal, as proposed in the guidelines for the diagnosis of C1-INH-HAE [2,23,26-27]. Patients were diagnosed as C1-INH-HAE type I when functional and antigenic C1-INH were ≤ 50% of normal. Patients were classified as C1-INH-HAE type II when functional C1-INH was ≤50% and antigenic C1-INH was >50% of normal. Independent families were identified, and the first diagnosed member of a family was considered as proband. Thirty-eight patients answered a questionnaire about prophylactic and on-demand therapy and thirty-two patients about attacks and triggers. All patients provided their consent to use their data anonymously. This study was conducted in accordance with the Declaration of Helsinki and was approved by the Ethics Committee of the Belarusian Research Center for Pediatric Oncology Hematology and Immunology in Minsk.