Clinico-radiological features, molecular spectrum, and identification of prognostic factors in developmental and epileptic encephalopathy due to inosine triphosphate pyrophosphatase (ITPase) deficiency.

"all novel variants reported were deposited in the leiden open variation database (lovd https://www lovd nl ) with the following accession numbers: #0000831814 #0000831817 #0000831819 #0000831820 #0000831821 #0000831822 #0000831823 #0000831824 #0000831825 #0000831826 #0000831827 #0000831828 #0000831829 and #0000831830."

"CONFLICT OF INTERESTS Teresa Santiago‐Sim, Amy Dameron, and Hui Yang are employees of GeneDx, Inc. The remaining authors declare that there are no conflict of interests."

"We thank the patients and their families for their collaboration and consent to the publication of this paper. This study was funded by the MRC (MR/S01165X/1, MR/S005021/1, G0601943), The National Institute for Health Research University College London Hospitals Biomedical Research Centre, Rosetree Trust, Ataxia UK, MSA Trust, Brain Research UK, Sparks GOSH Charity, Muscular Dystrophy UK (MDUK), Muscular Dystrophy Association (MDA USA), and also supported by the National Institute for Health Research (NIHR) Oxford Biomedical Research Centre based at Oxford University Hospitals NHS Trust and the University of Oxford, the Wellcome Trust Core award (203141/Z/16/Z), the Instituto de Salud Carlos III (PI19/01310) (Co‐funded by European Regional Development Fund "A way to make Europe"), the Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), an initiative of the Instituto de Salud Carlos III (Ministerio de Ciencia e Innovación, Spain), Generalitat de Catalunya (URDCAT project, SLT002/16/00174; (AGAUR 2017: SGR 1428), and the CERCA Programme. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR, or the Department of Health. TSB's lab is supported by the Netherlands Organization for Scientific Research (ZonMW Veni, Grant 91617021), an Erasmus MC Fellowship 2017, and Erasmus MC Human Disease Model Award 2018. This work was supported by German Bundesministerium für Bildung und Forschung (BMBF) through the ERA PerMed project PerMiM (01KU2016A) and the German Network for Mitochondrial Disorders (mitoNET; 01GM1113C)"