Pravata, V.M.Omelková, M.Stavridis, M.P.Desbiens, C.M.Stephen, H.M.Lefeber, D.J.Gecz, J.Gundogdu, M.Õunap, K.Joss, S.Schwartz, C.E.Wells, L.van Aalten, D.M.F.2025-07-102025-07-102020European Journal of Human Genetics, 2020; 28(6):706-7141018-48131476-5438https://hdl.handle.net/2440/145826Intellectual disability (ID) is a neurodevelopmental condition that affects∼1% of the world population. In total 5−10% of ID cases are due to variants in genes located on the X chromosome. Recently, variants in OGT have been shown to co-segregate with X-linked intellectual disability (XLID) in multiple families. OGT encodes O-GlcNAc transferase (OGT), an essential enzyme that catalyses O-linked glycosylation with β-N-acetylglucosamine (O-GlcNAc) on serine/threonine residues of thousands of nuclear and cytosolic proteins. In this review, we compile the work from the last few years that clearly delineates a new syndromic form of ID, which we propose to classify as a novel Congenital Disorder of Glycosylation (OGT-CDG). We discuss potential hypotheses for the underpinning molecular mechanism(s) that provide impetus for future research studies geared towards informed interventions.en© The Author(s) 2020. This article is published with open access. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.Development; Neurodevelopmental disordersAnimalsHumansGenetic Diseases, X-LinkedSyndromeN-AcetylglucosaminyltransferasesPoint MutationCongenital Disorders of GlycosylationIntellectual DisabilityJournal article10.1038/s41431-020-0589-92024-02-28521988Gecz, J. [0000-0002-7884-6861]