Primary ciliary dyskinesia

Primary ciliary dyskinesia (PCD) is a rare, autosomal recessive genetic ciliopathy, that causes defects in the action of cilia lining the upper and lower respiratory tract, sinuses, Eustachian tube, middle ear, fallopian tube, and flagella of sperm cells. The alternative name of "immotile ciliary syndrome" is no longer favored as the cilia do have movement, but are merely inefficient or unsynchronized. When accompanied by situs inversus the condition is known as Kartagener syndrome.

Respiratory epithelial motile cilia, which resemble microscopic "hairs" (although structurally and biologically unrelated to hair), are complex organelles that beat synchronously in the respiratory tract, moving mucus toward the throat. Normally, cilia beat 7 to 22 times per second, and any impairment can result in poor mucociliary clearance, with subsequent upper and lower respiratory infection. Cilia also are involved in other biological processes (such as nitric oxide production), currently the subject of dozens of research efforts.

Signs and symptoms

Around 80% of people with primary ciliary dyskinesia experience respiratory problems beginning within a day of birth. Many have a collapsed lobe of the lung and blood oxygen low enough to require treatment with supplemental oxygen. Within the first few months of life, most develop a chronic mucus-producing cough and runny nose. The main consequence of impaired ciliary function is reduced or absent mucus clearance from the lungs, and susceptibility to chronic recurrent respiratory infections, including sinusitis, bronchitis, pneumonia, and otitis media.