Finding a single mutation in two families in the total cohort of over 270 Polish PCD families (i.e. including 172 patients screened for mutations in this study plus the remaining 98, in whom mutations in other genes had been previously identified) indicates that mutations in ZMYND10, accounting for ~0.7% of Polish PCD chromosomes, are not among the most frequent causes of PCD in Polish patients. The gene discussed is ZMYND10; the disease is primary ciliary dyskinesia.