Clinical manifestations and genotype of primary ciliary dyskinesia diagnosed in Korea: a nationwide, multicenter, retrospective study

Abstract Background: Primary ciliary dyskinesia (PCD) is a genetically heterogeneous disorder that leads to secondary ciliary dysfunction. PCD is a rare disease worldwide, and its data are limited in Korea. This study systematically evaluated the clinical symptoms, diagnostic characteristics, and treatment of pediatric PCD in Korea. Methods: The medical records of paediatric patients diagnosed with PCD from January 2000 to August 2021 were retrospectively evaluated in this Korean nationwide, multicenter study.Results: Overall, 42 patients were diagnosed with PCD in 15 medical institutions. The median age at diagnosis was 9.9±6.0 years (range: 0.5 months–25.5 years). Most patients (40/42) were born at full term, 18 (42.9%) had neonatal respiratory symptoms, and 15 (35.7%) had a history of admission to the neonatal intensive care unit. The most common complaint (59.5%) was chronic nasal symptoms. Among them, 18 patients had a PICADAR score over 5 points, 32 patients were diagnosed through transmission electron microscopy (TEM) and 14 patients through genetic studies. TEM mostly identified outer dynein arm defects (alone or combined with inner dynein arm defects, n = 16). The genes with the highest mutation rates were DNAH5 (three cases) and DNAAF1 (three cases). Chest computed tomography revealed bronchiectasis in 34 out of 42 patients.Conclusions: Although PCD is a rare disease, early diagnosis can improve prognosis. However, a single gold standard diagnostic method has not yet been established, and its prevalence may be low owing to misdiagnosis.