1. NEXMIF encephalopathy: an X-linked disorder with male and female phenotypic patterns
- Author
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Zaid Afawi, Shekeeb S. Mohammad, Geoffrey Wallace, Ayelet Zerem, Amy L Schneider, Kyra E. Stuurman, Deepak Gill, Alison M. Muir, Russell C. Dale, Gali Heimer, Martino Montomoli, Elena Gardella, Emmanuelle Ranza, Simone Mandelstam, Peter Procopis, Øyvind L. Busk, Christian Korff, Arjan Bouman, Boudewijn Gunning, Connie T.R.M. Stumpel, Yunus Balcik, Christa de Geus, Philipp S. Reif, Yue-Hua Zhang, Sameer M. Zuberi, Volodymyr Kharytonov, Sébastien Küry, Patrick Edery, Sebastien Moutton, Trine Bjørg Hammer, Hannah Stamberger, Joseph D. Symonds, Gaetan Lesca, Samuel F. Berkovic, Massimiliano Rossi, Danique R.M. Vlaskamp, Eric W. Klee, Mark T Mackay, Felix Rosenow, Erica L. Macke, Chirag Patel, Jacob Bie Granild-Jensen, Helenius J. Schelhaas, Danielle M. Andrade, Lynette G. Sadleir, Iris M de Lange, Roseline Caumes, Eva Morava, Frédéric Tran Mau-Them, Anita Cairns, Keren Yosovich, Jing Zhang, Bruria Ben Zeev, Nicolas Chatron, Dorit Lev, Laura Reed, Pauline Monin, Eva H. Brilstra, Birgitte Bertelsen, Georgie Hollingsworth, Nienke E. Verbeek, Heather C Mefford, Rikke S. Møller, Johan R. Helle, Christina Fenger, Meriel McEntagart, Thomas Smol, Mark F. Bennett, Yuri A. Zarate, Renzo Guerrini, Elena Parrini, Candace T. Myers, Judith S. Verhoeven, Bertrand Isidor, Ruth Shalev, David A. Koolen, Ingrid E. Scheffer, Bobby P. C. Koeleman, Lauren Gunderson, Michael S. Hildebrand, Tara Sadoway, Richard J. Leventer, Sanjay M. Sisodiya, Krati Shah, Edith P. Almanza Fuerte, RS: GROW - R4 - Reproductive and Perinatal Medicine, MUMC+: DA KG Polikliniek (9), Klinische Genetica, and Clinical Genetics
- Subjects
Male ,Pediatrics ,medicine.medical_specialty ,INTELLECTUAL DISABILITY ,Autism Spectrum Disorder ,Encephalopathy ,Nerve Tissue Proteins ,ILAE COMMISSION ,MOSAICISM ,Epilepsy/genetics ,CLASSIFICATION ,Epilepsy ,Brain Diseases/genetics ,Genes, X-Linked ,Seizures ,Intellectual disability ,Genotype ,medicine ,Humans ,developmental and epileptic encephalopathy ,MYOCLONIA ,Atonic seizure ,Genetics (clinical) ,Brain Diseases ,ddc:618 ,Neurodevelopmental disorders Donders Center for Medical Neuroscience [Radboudumc 7] ,KIAA2022 ,business.industry ,MUTATIONS ,medicine.disease ,Phenotype ,Autism Spectrum Disorder/genetics ,Genes, X-Linked/genetics ,Autism spectrum disorder ,intellectual disability ,NEXMIF ,Autism ,epilepsy ,Female ,INACTIVATION ,Human medicine ,Seizures/genetics ,business ,POSITION PAPER - Abstract
Contains fulltext : 231688.pdf (Publisher’s version ) (Closed access) PURPOSE: Pathogenic variants in the X-linked gene NEXMIF (previously KIAA2022) are associated with intellectual disability (ID), autism spectrum disorder, and epilepsy. We aimed to delineate the female and male phenotypic spectrum of NEXMIF encephalopathy. METHODS: Through an international collaboration, we analyzed the phenotypes and genotypes of 87 patients with NEXMIF encephalopathy. RESULTS: Sixty-three females and 24 males (46 new patients) with NEXMIF encephalopathy were studied, with 30 novel variants. Phenotypic features included developmental delay/ID in 86/87 (99%), seizures in 71/86 (83%) and multiple comorbidities. Generalized seizures predominated including myoclonic seizures and absence seizures (both 46/70, 66%), absence with eyelid myoclonia (17/70, 24%), and atonic seizures (30/70, 43%). Males had more severe developmental impairment; females had epilepsy more frequently, and varied from unaffected to severely affected. All NEXMIF pathogenic variants led to a premature stop codon or were deleterious structural variants. Most arose de novo, although X-linked segregation occurred for both sexes. Somatic mosaicism occurred in two males and a family with suspected parental mosaicism. CONCLUSION: NEXMIF encephalopathy is an X-linked, generalized developmental and epileptic encephalopathy characterized by myoclonic-atonic epilepsy overlapping with eyelid myoclonia with absence. Some patients have developmental encephalopathy without epilepsy. Males have more severe developmental impairment. NEXMIF encephalopathy arises due to loss-of-function variants.
- Published
- 2021