Acquired angioedema appears similar to HAE with C1-INH deficiency, but this is not hereditary and more commonly affects those > 40 years.1,65–71 This form is most commonly due to catabolism of C1-INH, although some patients may have a lymphoproliferative or autoimmune disorder.1,65–71. The gene discussed is SERPING1; the disease is hyperinsulinemic hypoglycemia, familial, 4.