Biallelic loss of human CTNNA2, encoding αN-catenin, leads to ARP2/3 complex overactivity and disordered cortical neuronal migration
- Nat Genet. 2018 Aug;50(8):1093-1101. doi: 10.1038/s41588-018-0166-0.
- 1. Department of Neuroscience, Rady Children's Institute for Genomic Medicine, Howard Hughes Medical Institute, University of California, San Diego, San Diego, CA, USA. [email protected].
- 2. Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, OH, USA. [email protected].
- 3. Department of Neuroscience, Rady Children's Institute for Genomic Medicine, Howard Hughes Medical Institute, University of California, San Diego, San Diego, CA, USA.
- 4. Departments of Neurosurgery, Neurobiology, and Genetics, Yale University School of Medicine, New Haven, CT, USA.
- 5. Department of Medical Genetics, Istanbul Bilim University, Istanbul, Turkey.
- 6. Department of Pediatrics, Johns Hopkins Aramco Healthcare, Dhahran, Saudi Arabia.
- 7. Department of Pediatrics, Istanbul Bilim University, Istanbul, Turkey.
- 8. Department of Pediatrics, Yıldırım Beyazıt University, Ankara, Turkey.
- 9. Clinical Genetics Department, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt.
- 10. Clinical and Metabolic Genetics Section, Department of Pediatrics, Hamad Medical Corporation, Doha, Qatar.
- 11. Kariminejad-Najmabadi Pathology and Genetic Center, Tehran, Iran.
- 12. Department of Medical Genetics, Koç University School of Medicine, Istanbul, Turkey.
- 13. Mashhad Medical Genetic Counseling Center, Mashhad, Iran.
- 14. University of Tripoli, Tripoli Children's Hospital, Tripoli, Libya.
- 15. L.E.S. Mikrogen Genetic Diseases Diagnosis Center, Istanbul, Turkey.
- 16. Department of Pediatrics, Biochemical Genetics Program, University of California, San Diego, San Diego, CA, USA.
- 17. Department of Pediatric Neurology, Kocaeli University, Kocaeli, Turkey.
- 18. Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, OH, USA.
- 19. Department of Pediatric Neurology, Cukurova University, Adana, Turkey.
- 20. Department of Clinical Genetics, Christian Medical College and Hospital, Vellore, India.
- 21. Pediatric Genetics Unit, Department of Pediatrics, Acibadem Mehmet Ali Aydinlar University, Istanbul, Turkey.
- 22. Section of Medical Genetics, Department of Pediatrics, King Fahad Medical City, Children's Hospital, Riyadh, Saudi Arabia.
- 23. Department of Pediatrics, MediClubGeorgia, Tbilisi, Georgia.
- 24. Pediatric Department, Neuropediatric Unit, Cairo University Children's Hospital, Cairo, Egypt.
- 25. Neurology Department, Nicklaus Children's Hospital, Miami, FL, USA.
- 26. Arabkir Joint Medical Center and Institute of Child and Adolescent Health, Yerevan, Armenia.
- 27. Institut Cochin, Université Paris-Descartes, CNRS (UMR 8104), Paris, France.
- 28. Departments of Pediatrics and Neurology, University of Washington, Seattle, WA, USA.
- 29. Institute of Human Genetics, University of Leipzig Hospitals and Clinics, Leipzig, Germany.
- 30. Department of Neuroscience, Rady Children's Institute for Genomic Medicine, Howard Hughes Medical Institute, University of California, San Diego, San Diego, CA, USA. [email protected].
Neuronal migration defects, including pachygyria, are among the most severe developmental brain defects in humans. Here, we identify biallelic truncating mutations in CTNNA2, encoding αN-catenin, in patients with a distinct recessive form of pachygyria. CTNNA2 was expressed in human cerebral cortex, and its loss in neurons led to defects in neurite stability and migration. The αN-catenin paralog, αE-catenin, acts as a switch regulating the balance between β-catenin and Arp2/3 actin filament activities1. Loss of αN-catenin did not affect β-catenin signaling, but recombinant αN-catenin interacted with purified actin and repressed ARP2/3 actin-branching activity. The actin-binding domain of αN-catenin or ARP2/3 inhibitors rescued the neuronal phenotype associated with CTNNA2 loss, suggesting ARP2/3 de-repression as a potential disease mechanism. Our findings identify CTNNA2 as the first catenin family member with biallelic mutations in humans, causing a new pachygyria syndrome linked to actin regulation, and uncover a key factor involved in ARP2/3 repression in neurons.