Mutations in CCNO result in congenital mucociliary clearance disorder with reduced generation of multiple motile cilia

Nat Genet. 2014 Jun;46(6):646-51. doi: 10.1038/ng.2961. Epub 2014 Apr 20.


Using a whole-exome sequencing strategy, we identified recessive CCNO (encoding cyclin O) mutations in 16 individuals suffering from chronic destructive lung disease due to insufficient airway clearance. Respiratory epithelial cells showed a marked reduction in the number of multiple motile cilia (MMC) covering the cell surface. The few residual cilia that correctly expressed axonemal motor proteins were motile and did not exhibit obvious beating defects. Careful subcellular analyses as well as in vitro ciliogenesis experiments in CCNO-mutant cells showed defective mother centriole generation and placement. Morpholino-based knockdown of the Xenopus ortholog of CCNO also resulted in reduced MMC and centriole numbers in embryonic epidermal cells. CCNO is expressed in the apical cytoplasm of multiciliated cells and acts downstream of multicilin, which governs the generation of multiciliated cells. To our knowledge, CCNO is the first reported gene linking an inherited human disease to reduced MMC generation due to a defect in centriole amplification and migration.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Amino Acid Sequence
  • Animals
  • Cell Movement
  • Centrioles / metabolism
  • Child
  • Child, Preschool
  • Cilia / metabolism*
  • Cytoplasm / metabolism
  • DNA Glycosylases / genetics*
  • Female
  • Humans
  • Kartagener Syndrome / genetics*
  • Male
  • Mice
  • Models, Genetic
  • Molecular Sequence Data
  • Mucociliary Clearance / genetics*
  • Mutation*
  • Pedigree
  • Sequence Analysis, DNA
  • Sequence Homology, Amino Acid
  • Xenopus laevis


  • CCNO protein, human
  • DNA Glycosylases