Although there is not a consensus definition for the FAO phenotype, it have been recognized as an asthma phenotype differentiated from COPD54–58 and explained by the progressive decline in FEV1 as a result of airway remodelling asscociated with allergic airway inflammation, allergen exposure and elevated IgE levels throughout life, in agreement with this is the fact that NAO patients were younger than the patients in the other phenotypes. This evidence concerns the gene IGHE and asthma.