YIPF5 mutations cause neonatal diabetes and microcephaly through endoplasmic reticulum stress
- J Clin Invest. 2020 Dec 1;130(12):6338-6353. doi: 10.1172/JCI141455.
- 1. Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, United Kingdom.
- 2. ULB Center for Diabetes Research and.
- 3. Division of Endocrinology, Erasmus Hospital, Université Libre de Bruxelles, Brussels, Belgium.
- 4. Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland.
- 5. Endocrinology and Metabolism, Department of Medicine and Surgery, University of Parma, Parma, Italy.
- 6. Electron Microscopy Unit, Institute of Biotechnology, University of Helsinki, Helsinki, Finland.
- 7. Yeditepe University Hospital, Istanbul, Turkey.
- 8. Gazi Yaşargil Education and Research Hospital, Diyarbakır, Turkey.
- 9. Dicle University, Faculty of Medicine, Department of Pediatric Endocrinology, Diyarbakır, Turkey.
- 10. Harmony Health Hub, Nashik, India.
- 11. Istanbul University, Istanbul Faculty of Medicine, Department of Pediatric Endocrinology, Istanbul, Turkey.
- 12. Kanuni Sultan Suleyman Training and Research Hospital, Department of Pediatric Endocrinology, Istanbul, Turkey.
- 13. Institute of Interdisciplinary Research (IRIBHM), ULB Neuroscience Institute, Université Libre de Bruxelles, Brussels, Belgium.
- 14. VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium.
- 15. Department of Neurosciences, Leuven Brain Institute, KU Leuven, Leuven, Belgium.
- 16. Welbio, Université Libre de Bruxelles, Brussels, Belgium.
- 17. Université de Paris, Faculté de Médecine Paris-Diderot, U958, Paris, France.
- 18. Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.
- 19. Indiana Biosciences Research Institute, Indianapolis, Indiana, USA.
- 20. Children's Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.
Neonatal diabetes is caused by single gene mutations reducing pancreatic β cell number or impairing β cell function. Understanding the genetic basis of rare diabetes subtypes highlights fundamental biological processes in β cells. We identified 6 patients from 5 families with homozygous mutations in the YIPF5 gene, which is involved in trafficking between the endoplasmic reticulum (ER) and the Golgi. All patients had neonatal/early-onset diabetes, severe microcephaly, and epilepsy. YIPF5 is expressed during human brain development, in adult brain and pancreatic islets. We used 3 human β cell models (YIPF5 silencing in EndoC-βH1 cells, YIPF5 knockout and mutation knockin in embryonic stem cells, and patient-derived induced pluripotent stem cells) to investigate the mechanism through which YIPF5 loss of function affects β cells. Loss of YIPF5 function in stem cell-derived islet cells resulted in proinsulin retention in the ER, marked ER stress, and β cell failure. Partial YIPF5 silencing in EndoC-βH1 cells and a patient mutation in stem cells increased the β cell sensitivity to ER stress-induced Apoptosis. We report recessive YIPF5 mutations as the genetic cause of a congenital syndrome of microcephaly, epilepsy, and neonatal/early-onset diabetes, highlighting a critical role of YIPF5 in β cells and neurons. We believe this is the first report of mutations disrupting the ER-to-Golgi trafficking, resulting in diabetes.