New insights in primary ciliary dyskinesia

Introduction: Primary ciliary dyskinesia (PCD) is a rare genetic disease with an estimated prevalence of 1:20.000 births. It is characterized by abnormal motility of cilia, leading to impaired mucociliary clearance, and subsequent infection and chronic inflammation of the airways. PCD also affects spermatozoa and cilia in the Fallopian tubes, contributing to fertility issues; dyskinesia of embryonic nodal cilia causes a random distribution of the organs. Areas covered: An overview of the history, genetics, clinical manifestations in children and adults, diagnostic tests, treatments, and prognosis are reviewed. We also discuss current research and future prospects of PCD. Expert opinion: As PCD comprises defects in all organs with motile cilia, patients have a variety of clinical manifestations, often characterized by their presence from birth. Because of the non-specific symptoms, PCD is often confused with other diseases such as cystic fibrosis. There is no gold standard diagnostic test and a variety of diagnostic tests are required, including high-speed video analysis and transmission electron microscopy. Reanalysis following primary cultures of the epithelial cells can help to differentiate primary from secondary defects. Despite being a genetic disease, due to the genetic heterogeneity of PCD, gene analysis can currently only explain 65% of the cases. There is no treatment for PCD, and therapeutic options that contribute to the wellbeing of the patients are based on expert opinion.