The clinical presentation of HAE-nl-C1-INH is similar to that of HAE-C1-INH but with some differences, including more frequent swelling of the face and tongue rather than abdominal symptoms.85 Because the underlying causes of HAE-nl-C1-INH are genetic mutations, genetic testing may be helpful in the diagnosis of these patients. This evidence concerns the gene SERPING1 and hereditary angioedema.