HAE is divided into two types, HAE with C1 esterase inhibitor deficiency (C1INH) named HAE-C1INH, caused by mutations in the SERPING1 gene, coding for C1INH and HAE without C1INH deficiency, known as HAE with normal C1INH (HAE-nC1INH) (1). The gene discussed is SERPING1; the disease is hereditary angioedema.