C4A and angioedema: Based on the current guidelines, molecular genetic testing is not obligatory as a first-line diagnostic approach in case of patients with angioedema, as most of the cases can be diagnosed based on the clinical picture, complement laboratory findings (functional and antigenic levels of C1-inhibitor, concentrations of C4, C1q, and autoantibodies against C1-inhibitor) as well as family history (if available) (9).