PCD is a rare disorder and is associated with defective ciliary structure and function causing alterations in mucociliary clearance. This condition gives rise to severe, chronic airway disorder with progressive loss of lung function and severe consequences in adulthood. There is poor knowledge on the prevalence of this disease and this seems to differ from country to country. The aim of this study was to determine the distribution of PCD in Italy and to describe the population characteristics. Our study population consisted of 331 patients from 26 participating centers, of which 292 with a definitive diagnosis of PCD established by combining clinical features, the ciliary beat pattern, cilia ultrastructure studies and/or genetic defects.

292 PCD patients (146 M, aged 0–70 years) belonged to 260 families;38 with >one member affected and 17 consanguineous families. Mean age at diagnosis was 13.4 yrs ± 13 (median age 9), which decreased significantly in the pediatric population (mean 5.1 yrs). Situs inversus was present in 56.8% and age of diagnosis was significantly lower with respect to situs solitus (4.2 vs 13.0 yrs). In conclusion, this study suggests that the prevalence of PCD in Italy is higher than generally considered. Moreover, our data show that this disorder is not only lately diagnosed but also underdiagnosed as in other European countries.Project financed by the Italian Health Ministry (RF-VEN-2008-1201767).