Acquired angioedema due to C1-inhibitor (C1-INH) deficiency (AAE-C1-INH) or angioedema due to acquired C1-INH deficiency is characterized by acquired deficiency of C1-INH, recurrent angioedema, and hyperactivation of the complement pathway. This evidence concerns the gene SERPING1 and hyperinsulinemic hypoglycemia, familial, 4.