Chronic pulmonary disease associated with an unusual genetic type of α1 -antitrypsin deficiency in childhood

Chronic pulmonary disease (CPD) occurs in most individuals with the common α1-antitrypsin (α1AT) deficiency phenotype, PiZZ, and less frequently in heterozygotes (PiMZ; normal = PiMM). A few other variants are associated with lesser degress of deficiency, but their roles in pathogenesis of disease are unclear. For example, the incidence of CPD in PiSS and PiSZ individuals is not known, although Fagerhol has reported that these phenotypes may predispose to CPD. His two patients had asthma and chronic bronchitis rather than emphysema per se.