Hereditary angioneurotic oedema.

Three families with hereditary angioneurotic oedema (HANE) are described. Serum CI-INH and C4 immunochemical determinations were performed on 23 members of the families: in 6 persons low CI-INH and C4 levels were found with typical symptoms of HANE, and in one asymptomatic subject. Normal ranges of both proteins for adults, children and newborns are given for comparative purposes. The importance of the early diagnosis and treatment is emphasized.