The first attacks occurred before the age of 12 in 26 patients (24 C1-INH-INH, 2 F12-HAE) (mean = 6.7 years); between 12 and 25 years of age in 21 patients (20 C1-INH-HAE, 5 F12-HAE) (mean = 17), and after 25 years of age in eight (3 C1-INH-HAE, 5 F12-HAE) (mean = 33.8). This evidence concerns the gene SERPING1 and hereditary angioedema.