Germline De Novo Mutations in GNB1 Cause Severe Neurodevelopmental Disability, Hypotonia, and Seizures
- Am J Hum Genet. 2016 May 5;98(5):1001-1010. doi: 10.1016/j.ajhg.2016.03.011.
- 1. Institute for Genomic Medicine, Columbia University, New York, NY 10032, USA; Department of Medicine, Austin Health and Royal Melbourne Hospital, University of Melbourne, Melbourne, VIC 3050, Australia. Electronic address: [email protected].
- 2. Service de Génétique Médicale, Centre Hospitalier Universitaire Nantes, Nantes 44093, France.
- 3. Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle WA, 98195, USA.
- 4. Division of Clinical Genetics, Department of Pediatrics, Columbia University Medical Center, New York, NY 10032, USA.
- 5. Division of Medical Genetics, Northwell Health, Manhasset, NY 11030, USA.
- 6. Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
- 7. Institute for Genomic Medicine, Columbia University, New York, NY 10032, USA.
- 8. Division of Medical Genetics, Department of Pediatrics, Stanford University School of Medicine, Stanford, CA 94305, USA.
- 9. Section of Genetics, Department of Pediatrics, University of Oklahoma, Oklahoma City, OK 73019, USA.
- 10. School of Women's and Children's Health, University of New South Wales, Kensington, NSW 2052, Australia.
- 11. Genetics of Learning Disability Service, Hunter Genetics, Waratah, NSW 2298, Australia; Priority Research Centre GrowUpWell, University of Newcastle, Callaghan, NSW 2308, Australia.
- 12. Department of Medicine, Austin Health, University of Melbourne, Heidelberg, VIC 3081, Australia.
- 13. Department of Neurosciences, Royal Children's Hospital, Herston School of Medicine, University of Queensland, Brisbane, QLD 4072, Australia.
- 14. Service de Stomatologie, Centre Hospitalier Universitaire Nantes, Nantes 44093, France.
- 15. Department of Neurology, University of Minnesota, Minneapolis, MN 55454, USA.
- 16. Division of Genetics, Department of Pediatrics, Albany Medical Center, Albany, NY 12208, USA.
- 17. Phoenix Children's Hospital and Department of Child Health, University of Arizona College of Medicine, Phoenix, AZ 85724, USA.
- 18. Cook Children's Physician Network, Fort Worth, TX 76102, USA.
- 19. Division of Medical Genetics, Department of Pediatrics, University of Texas Health Science Center at Houston, Houston, TX 77030, USA.
- 20. Department of Medicine, Austin Health, University of Melbourne, Heidelberg, VIC 3081, Australia; Florey Institute for Neuroscience and Mental Health, University of Melbourne, Parkville, VIC 3050, Australia; Department of Paediatrics, Royal Children's Hospital, University of Melbourne, Melbourne, VIC 3050, Australia.
- 21. Institute for Genomic Medicine, Columbia University, New York, NY 10032, USA. Electronic address: [email protected].
Whole-exome Sequencing of 13 individuals with developmental delay commonly accompanied by abnormal muscle tone and seizures identified de novo missense mutations enriched within a sub-region of GNB1, a gene encoding the guanine nucleotide-binding protein subunit beta-1, Gβ. These 13 individuals were identified among a base of 5,855 individuals recruited for various undiagnosed genetic disorders. The probability of observing 13 or more de novo mutations by chance among 5,855 individuals is very low (p = 7.1 × 10(-21)), implicating GNB1 as a genome-wide-significant disease-associated gene. The majority of these 13 mutations affect known Gβ binding sites, which suggests that a likely disease mechanism is through the disruption of the protein interface required for Gα-Gβγ interaction (resulting in a constitutively active Gβγ) or through the disruption of residues relevant for interaction between Gβγ and certain downstream effectors (resulting in reduced interaction with the effectors). Strikingly, 8 of the 13 individuals recruited here for a neurodevelopmental disorder have a germline de novo GNB1 mutation that overlaps a set of five recurrent somatic tumor mutations for which recent functional studies demonstrated a gain-of-function effect due to constitutive activation of G protein downstream signaling cascades for some of the affected residues.