Moreover, a similar result is also reported by a retrospective study of 114 AATD patients in a Portuguese hospital, who underwent a CT scan: 29.8% had HRCT evidence of bronchiectasis, AAT mean serum level was 66.0 ± 33.9 mg/dL, and patients with bronchiectasis had lower AAT serum levels (p = 0.015). The gene discussed is SERPINA1; the disease is alpha 1-antitrypsin deficiency.