Angioedema Hereditary Underlying Cause
The cause of hereditary angioedema is an abnormal gene that results in low levels of C1 inhibitor protein. C1 inhibitor protein prevents episodes of inflammation in the body. When levels of the protein are low, inflammation occurs much more easily in all tissues of the body.
Factors that may trigger episodes of swelling in those with hereditary angioedema include:
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- Nzeako UC, Frigas E, Tremaine WJ. Hereditary angioedema: a broad review for clinicians. Arch Intern Med. 2001 Nov 12;161(20):2417-29. 
- Zuraw BL. Current and future therapy for hereditary angioedema. Clin Immunol. 2005 Jan;114(1):10-6.