Primary ciliary dyskinesia: a multicenter study assessing genotype -phenotype association in Italy.

<bold>INTRODUCTION:</bold> Primary ciliary dyskinesia (PCD) is a rare genetic disorder characterized by abnormalities in the structure and/or motility of motile cilia. Genetics could be important in defining prognosis. <bold>AIM:</bold> To study the genotype-clinical phenotype correlation in patients with PCD followed at two Italian centers. MATERIALS AND METHODS We enrolled PCD confimed patients that have been followed up for at least six months in two centers of Itlay: Policlinico Umberto I – Sapienza University of Rome and Spedali Civili di Brescia from March 2020 to March 2023. A data collection form was completed for each patient consulting medical records. <bold>Results:</bold> A total of 39 patients with confirmed PCD were enrolled. The genetic defect was identified in 29/39 patients (74.4%), while a diagnostic TEM was found in 29/35, TEM- genotype correlation is shown in Figure 1. Assessing the genotype-phenotype correlation, patients with mutations in CCDC39/40 genes more frequently presented with ventilatory deficit on spirometry ("DNAH5" vs. "CCDC39/40" vs. "Others" respectively 25.0% vs. 88.9% vs. 55.6%, p=0.029) and a significantly lower FEV1% value (p= 0.017) than the other two groups. <bold>Conclusions:</bold> PCD is an extremely heterogeneous disorder. Patients with pathogenic mutations in the CCDC39 and CCDC40 genes have worse symptoms and respiratory function are therefore worthy of closer follow-up. Fig 1: Genotype-TEM correlation. <fig><object-id>erj;64/suppl_68/PA2256/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig>