Primary Ciliary Dyskinesia: an Overlooked Orphan Disease?

Abstract

Primary Ciliary Dyskinesia (PCD) is a genetically heterogeneous disorder of motile cilia which affects mucociliary clearance. This leads to chronic problems of the upper and lower respiratory tract and in around 50% of cases to mirror image arrangement. Ciliary dysfunction results in an array of clinical manifestations including chronic bronchitis leading to bronchiectasis, chronic rhinosinusitis, and otitis media, male infertility. The low estimated incidence situates PCD among orphan diseases. Establishing the diagnosis is a difficult task and is usually based on clinical suspicion followed by a series of investigations (nasal nitric oxide measurements, in vivo tests of ciliary motility examination of cilia by electron microscopy, epithelial cultures, and genetic testing) that will be described in this article. Despite new genetic findings, PCD is still an underdiagnosed disorder. An overview of the literature is made, followed by an illustration of suggestive case reports.