© 2017, GENASSIST, Inc.
By Keith S. Wexler, MBA, Maternal Fetal Medicine, Prenatal Diagnosis and Biotech/Life Sciences Consultant, GENASSIST, Inc.
Paul Wexler, M.D., F.A.C.O.G., Medical Director, GENASSIST, Inc.
Clinical Professor, Department of OB/GYN, University of Colorado Health Sciences Center
Clinical Professor, Division of Genetics/Dept. of Pediatrics, Univ. of Colorado/The Children’s Hospital
Hereditary Angioedema (HAE): Is an uncommon genetic disorder which is either sporadic (approximately 20-25% of cases) or inherited (risk may be as high as 50% for a child of either sex if inherited in an autosomal dominant manner).
Symptoms usually include swelling of the face, lips and respiratory tract and can involve the intestines. Usually self-limiting in 2-5 days; rarely swelling of the upper airway can be life threatening.
Three types of disorders have been described:
- Type I: In which C1-inhibitor synthesis is reduced
- Type II: In which an abnormal protein is formed
- Type III: Usually occurring in women and precipitated by pregnancy or birth control pills in which C1 (complement) inhibitor is normal
Steroids, adrenaline and antihistamines are not very effective. Several new drugs which inhibit Kallekrein or the bradykinin B2 receptor have been used.
Type III in which Factor XII levels are diminished has been treated with progesterone, antifibrinolytics (tranexamic acid) or Danacrine has been used.
Withdrawal of estrogen and completion of pregnancy has resulted in remission of Type III disease.
Several new types of C1 inhibitors for use with in patients with HAE with low or abnormal complement [Cinyze, Berinert, Reconest (recombinant), the Kallekrein antagonist (Kalbitor)and the bradykinin receptor antagonist (Firazr) have been FDA approved.