Primary ciliary dyskinesia (PCD), also known as Kartagener syndrome, is a genetic disorder of the cilia, which are microscopic hair-like cells. Cilia work to keep the respiratory system clean by moving mucus that contains debris to the large airways, where it can be coughed out. People with PCD have cilia that do not move properly and therefore are not effective in cleaning the respiratory system. This study will determine when PCD starts and how it changes over time, specifically in terms of how well the lungs work, what germs grow in lung secretions, and how the lungs look on computed tomography (CT) scans.