Clinical Manifestations and Genotype of Primary Ciliary Dyskinesia Diagnosed in Korea: Multicenter Study

PURPOSE: Primary ciliary dyskinesia (PCD) is a genetically heterogeneous disorder that leads to secondary ciliary dysfunction. PCD is a rare disease, and data on it are limited in Korea. This study systematically evaluated the clinical symptoms, diagnostic characteristics, and treatment modalities of pediatric PCD in Korea. METHODS: This Korean nationwide, multicenter study, conducted between January 2000 and August 2022, reviewed the medical records of pediatric patients diagnosed with PCD. Prospective studies have been added to determine whether additional genetic testing is warranted in some patients. RESULTS: Overall, 41 patients were diagnosed with PCD in 15 medical institutions. The mean age at diagnosis was 11.8 ± 5.4 years (range: 0.5 months-18.9 years). Most patients (40/41) were born full term, 15 (36.6%) had neonatal respiratory symptoms, and 12 (29.3%) had a history of admission to the neonatal intensive care unit. The most common complaint (58.5%) was chronic nasal symptoms. Thirty-three patients were diagnosed with transmission electron microscopy (TEM) and 12 patients by genetic studies. TEM mostly identified outer dynein arm defects (alone or combined with inner dynein arm defects, n = 17). The genes with the highest mutation rates were DNAH5 (3 cases) and DNAAF1 (3 cases). Rare genotypes (RPGR, HYDIN, NME5) were found as well. Chest computed tomography revealed bronchiectasis in 33 out of 41 patients. Among them, 15 patients had a PrImary CiliAry DyskinesiA Rule score of over 5 points. CONCLUSIONS: To our knowledge, this is the first multicenter study to report the clinical characteristics, diagnostic methods, and genotypes of PCD in Korea. These results can be used as basic data for further PCD research.