Pathogenic variants in CLXN encoding the outer dynein arm docking–associated calcium-binding protein calaxin cause primary ciliary dyskinesia

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Rim Hjeij - , University of Münster (Author)
  • Isabella Aprea - , University of Münster (Author)
  • Marco Poeta - , Universita' di Napoli Federico II (Author)
  • Tabea Nöthe-Menchen - , University of Münster (Author)
  • Diana Bracht - , University of Münster (Author)
  • Johanna Raidt - , University of Münster (Author)
  • Barbara I. Honecker - , University of Münster (Author)
  • Gerard W. Dougherty - , University of Münster (Author)
  • Heike Olbrich - , University of Münster (Author)
  • Oliver Schwartz - , University of Münster (Author)
  • Ulrike Keller - , University of Münster (Author)
  • Harald Nüsse - , University of Münster (Author)
  • Karin E.M. Diderich - , Erasmus University Rotterdam (Author)
  • Christian Vogelberg - , Department of Paediatrics, TUD Dresden University of Technology (Author)
  • Francesca Santamaria - , Universita' di Napoli Federico II (Author)
  • Heymut Omran - , University of Münster (Author)

Abstract

Purpose: Primary ciliary dyskinesia (PCD) is a heterogeneous disorder that includes respiratory symptoms, laterality defects, and infertility caused by dysfunction of motile cilia. Most PCD-causing variants result in abnormal outer dynein arms (ODAs), which provide the generative force for respiratory ciliary beating and proper mucociliary clearance. Methods: In addition to studies in mouse and planaria, clinical exome sequencing and functional analyses in human were performed. Results: In this study, we identified homozygous pathogenic variants in CLXN (EFCAB1/ODAD5) in 3 individuals with laterality defects and respiratory symptoms. Consistently, we found that Clxn is expressed in mice left-right organizer. Transmission electron microscopy depicted ODA defects in distal ciliary axonemes. Immunofluorescence microscopy revealed absence of CLXN from the ciliary axonemes, absence of the ODA components DNAH5, DNAI1, and DNAI2 from the distal axonemes, and mislocalization or absence of DNAH9. In addition, CLXN was undetectable in ciliary axonemes of individuals with defects in the ODA-docking machinery: ODAD1, ODAD2, ODAD3, and ODAD4. Furthermore, SMED-EFCAB1-deficient planaria displayed ciliary dysmotility. Conclusion: Our results revealed that pathogenic variants in CLXN cause PCD with defects in the assembly of distal ODAs in the respiratory cilia. CLXN should be referred to as ODA-docking complex–associated protein ODAD5.

Details

Original languageEnglish
Article number100798
JournalGenetics in medicine
Volume25
Issue number5
Publication statusPublished - May 2023
Peer-reviewedYes

External IDs

PubMed 36727596

Keywords

ASJC Scopus subject areas

Keywords

  • EFCAB1, Laterality defects, ODA, ODAD, PCD, Axoneme/genetics, Calcium-Binding Proteins, Humans, Axonemal Dyneins/genetics, Kartagener Syndrome/genetics, Animals, Mice, Mutation, Cilia/genetics