ABSTRACT
Abstract: Background: Hereditary angioedema is a rare autosomal dominantly inherited immunodeficiency disorder characterized by potentially life-threatening angioedema attacks. Objective: We aimed to investigate the clinical and genetic features of a family with angioedema attacks. Methods: The medical history, clinical features and C1-INH gene mutation of a Turkish family were investigated and outcomes of long-term treatments were described. Results: Five members had experienced recurrent swellings on the face and extremities triggered by trauma. They were all misdiagnosed as familial Mediterranean fever (FMF) depending on frequent abdominal pain and were on colchicine therapy for a long time. They had low C4 and C1-INH protein concentrations and functions. A mutation (c.1247T>A) in C1-INH gene was detected. They were diagnosed as having hereditary angioedema with C1-INH deficiency (C1-INH hereditary angioedema) for the first time. Three of them benefited from danazol treatment without any significant adverse events and one received weekly C1 esterase replacement treatment instead of danazol since she had a medical history of thromboembolic stroke. Study limitations: Small sample size of participants. Conclusion: Patients with C1-INH hereditary angioedema may be misdiagnosed as having familial Mediterranean fever in regions where the disorder is endemic. Medical history, suspicion of hereditary angioedema and laboratory evaluations of patients and their family members lead the correct diagnoses of hereditary angioedema. Danazol and C1 replacement treatments provide significant reduction in hereditary angioedema attacks.