Rare genetic respiratory disorders such as cystic fibrosis (CF, MIM 219700), alpha-1 antitrypsin deficiency (A1ATD, MIM 613490), lymphangioleiomyomatosis (LAM, MIM 606690) and primary ciliary dyskinesia (PCD, MIM 244400) are individually rare, but collectively common, affecting more than 1:2500 live births. The gene discussed is PSMA6; the disease is primary ciliary dyskinesia.