An autosomal dominant disorder (hereditary angioneurotic oedema) in which there is episodic local subcutaneous oedema and oedema involving the upper respiratory and gastrointestinal tracts (which can have fatal consequences by restricting breathing). Hereditary angioedema types I and II are caused by mutation in the complement C1 inhibitor gene, the product of which is a serine peptidase inhibitor (serpin). As a result there is uncontrolled production of C2-kinin. Type III occurs only in women and is precipitated or worsened by high oestrogen levels and is caused by mutation in the gene encoding coagulation factor XII (Hageman factor).
Subjects: Medicine and Health — Chemistry.