A hereditary angioedema screening on an index case

Background: Hereditary angioedema (HAE) is characterised by recurrent episodes of angioedema and can be fatal. Objective: The present study aimed to screen HAE. Methods: A total of 60 individuals were screened. The frequency and severity of symptoms were scored from 0 to 8. Measurements were taken of C4 and C1 esterase inhibitor protein (C1-INH) levels. Mutation in the C1 inhibitor gene was examined in 9 patients with HAE. Results: A positive correlation between the C1 esterase inhibitor protein levels and C4 level was detected in the group as a whole (p < 0.001, r = 0.725, n = 60). A negative correlation between the C1 esterase inhibitor protein level and severity score was observed in the whole group (p < 0.001, r = -0.486, n = 60). A negative correlation was also detected in the entire group between the C4 level and severity score (p = 0.002, r = -0.389, n = 60). In the patients with HAE, a positive correlation between the C1 esterase inhibitor protein level and C4 levels was detected (p = 0.034, r = 0.705, n = 9). A heterozygous c. 601A > T nonsense variant was identified at the C1 esterase inhibitor gene-SERPING1-in patients with Type 1 HAE. Conclusion: It is well known that there is a prolonged delay in the diagnosis of HAE. The present study demonstrates that it is very important and even life-saving to screen for HAE on the basis of an index case.