A Case of Primary Ciliary Dyskinesia Caused by CFTR Gene and SFTPC Gene Variants.

INTRODUCTION: This study retrospectively analyzed the clinical data of a female child with primary ciliary dyskinesia (PCD) caused by variants in the CFTR (NM_000492.3) and SFTPC (NM_003018.3). All variant descriptions in this report follow the HGVS standardized nomenclature guidelines. These two variants are considered to be potentially associated with pediatric PCD. CASE PRESENTATION: A 13-year-old Chinese female patient with a history of recurrent respiratory infections was admitted due to intermittent cough and sputum production for one month, exacerbated by fever for five days. Chest CT revealed a lung infection and bronchiectasis. Transmission electron microscopy of ciliary biopsy identified structural abnormalities in bronchial mucosa cilia, including aberrant microtubule arrangements (8 + 2, 9 + 1, and 7 + 2 patterns), and disorganized peripheral microtubules. The whole-exome sequencing (WES) identified a heterozygous variant c.374T > C (p.Ile125Thr) in CFTR (NM_000492.3) and a heterozygous variant c.115G > T (p.Val39Leu) in SFTPC (NM_003018.3), with all nomenclature complying with HGVS recommendations. A comprehensive diagnosis of PCD was confirmed. The patient improved after anti-infective and symptomatic therapy and was discharged. CONCLUSION: Variants in the CFTR and SFTPC genes may be associated with PCD in children. This case highlights the importance of early genetic variant testing and ciliary ultrastructural analysis (e.g., transmission electron microscopy) in children with recurrent respiratory tract infections, bronchiectasis, or chronic sinusitis, thereby facilitating timely diagnosis and clinical intervention.