CCDC39 and primary ciliary dyskinesia: In summary, we identified a homozygous variant and two compound heterozygous variants of CCDC39, which can be responsible for the pathogenesis of PCD and Kartagener syndrome in two cases, expanding the variant spectrum of PCD in Chinese patients involving CCDC39. And compound CCDC39 variants can also be identified in infertile male cases with MMAF.