Identification of a novel and recurrent mutation in the SERPING1 gene in patients with hereditary angioedema.

Hereditary angioedema (HAE) due to C1 inhibitor (C1-INH) deficiency is an autosomal dominant disorder caused by mutations in SERPING1 gene. More than 200 different mutations are known, with high genetic heterogeneity and high frequency of private familial mutations. We analyzed for genetic mutations the C1-INH locus in 11 Sardinian families, revealing in seven subjects from four unrelated families the novel nonsense mutation S318X. This mutation, detected with unexpected high frequency, accounts for over a third of the here reported Sardinian families affected by HAE. The recurrence of a pathogenic mutation within the same geographical area is a unique finding, previously unreported in HAE due to C1-INH deficiency.