The most frequent rearrangement affects the 12q15 band of the HMGIC gene.6 Clinical presentation due to the tracheobronchial localization of the HC is usually very noisy, either directly related to the trachea or the bronchial obstruction; in this case, the patient can be wrongly treated as asthma or COPD, as in our first patient, either in relation to its consequences, in particular obstructive pneumonia or destruction of the lung parenchyma with bronchiectasis, as in our second patient. This evidence concerns the gene HMGA2 and asthma.