Primary Ciliary Dyskinesia (PCD) is a rare, genetically heterogeneous disorder which results from the dysfunction of small hair-like organelles, called motile cilia. Motile cilia project from the apical side of epithelial cells that line up the upper and lower airways (respiratory cilia) and can be found in a variety of other tissues. PCD patients usually suffer from recurrent respiratory infections which lead to chronic destructive airway disease characterized by progressive loss of lung function and structural damage to the airways (bronchiectasis).