Germline variants in tumor suppressor FBXW7 lead to impaired ubiquitination and a neurodevelopmental syndrome

• DOI: 10.1016/j.ajhg.2022.03.002
• Publication Date: 2022-04-07T14:35:34Z
• Authors: Sarah E.M. Stephe...; Gregory Costain; Laura E.R. Blok; Michael A. Silk; Thanh Binh Nguyen; Xiaomin Dong; Dana E. Alhuzaimi; James J. Dowling; Susan Walker; Kimberly Amburgey; Robin Z. Hayeems; Lance H. Rodan; Marc A. Schwartz; Jonathan Picker; Sally A. Lynch; Aditi Gupta; Kristen J. Rasmussen; Lisa A. Schimmenti; Eric W. Klee; Zhiyv Niu; Katherine E. Agre; Ilana Chilton; Wendy K. Chung; Anya Revah-Politi; P.Y. Billie Au; Christopher Griffith; Melissa Racobaldo; Annick Raas-Roths...; Bruria Ben Zeev; Ortal Barel; Sebastien Moutton; Fanny Morice-Picard; Virginie Carmignac; Jenny Cornaton; Nathalie Marle; Orrin Devinsky; Chandler Stimach; Stephanie Burns W...; Bryan E. Hainline; Katie Sapp; Marjolaine Willems; Ange-line Bruel; Kerith-Rae Dias; Carey-Anne Evans; Tony Roscioli; Rani Sachdev; Suzanna E.L. Temple; Ying Zhu; Joshua J. Baker; Ingrid E. Scheffer; Fiona J. Gardiner; Amy L. Schneider; Alison M. Muir; Heather C. Mefford; Amy Crunk; Elizabeth M. Heise; Francisca Millan; Kristin G. Monaghan; Richard Person; Lindsay Rhodes; Sarah Richards; Ingrid M. Wentzensen; Benjamin Cogné; Bertrand Isidor; Mathilde Nizon; Marie Vincent; Thomas Besnard; Amelie Piton; Carlo Marcelis; Kohji Kato; Norihisa Koyama; Tomoo Ogi; Elaine Suk-Ying Goh; Christopher Richmond; David J. Amor; Jessica O. Boyce; Angela T. Morgan; Michael S. Hildeb...; Antony Kaspi; Melanie Bahlo; Rún Friðriksdóttir; Hildigunnur Katrí...; Patrick Sulem; Kári Stefánsson; Hans Tómas Björnsson; Simone Mandelstam; Manuela Morleo; Milena Mariani; Marcello Scala; Andrea Accogli; Annalaura Torella; Valeria Capra; Mathew Wallis; Sandra Jansen; Quinten Waisfisz; Hugoline de Haan; Simon Sadedin; Sze Chern Lim; Susan M. White; David B. Ascher; Annette Schenck; Paul J. Lockhart; John Christodoulou; Tiong Yang Tan
• Keywords: 0301 basic medicine; F-box protein; Proteasome Endopeptidase Complex; Brain malformation; F-Box-WD Repeat-Containing Protein 7; 572; Ubiquitin-Protein Ligases; Neurodevelopment; Global developmental delay; Intellectual disability; gastrointestinal issues; Radboud University Medical Center; Hypotonia; global developmental delay; 03 medical and health sciences; brain malformation; epilepsy; F-box protein; FBXW7; gastrointestinal issues; global developmental delay; hypotonia; intellectual disability; macrocephaly; Neurodevelopment; FBXW7; Gastrointestinal issues; Macrocephaly; Humans; hypotonia; Germ-Line Mutation; Epilepsy; Radboudumc 7: Neurodevelopmental disorders DCMN: Donders Center for Medical Neuroscience; macrocephaly.; brain malformation; Ubiquitination; [SDV] Life Sciences [q-bio]; Germ Cells; brain malformation; epilepsy; F-box protein; FBXW7; gastrointestinal issues; global developmental delay; hypotonia; intellectual disability; macrocephaly; Neurodevelopment; Germ Cells; Germ-Line Mutation; Humans; Proteasome Endopeptidase Complex; Ubiquitin-Protein Ligases; F-Box-WD Repeat-Containing Protein 7; Neurodevelopmental Disorders; Ubiquitination; intellectual disability; Neurodevelopmental Disorders; epilepsy; Human Genetics - Radboud University Medical Center

Neurodevelopmental disorders are highly heterogenous conditions resulting from abnormalities of brain architecture and/or function. FBXW7 (F-box and WD-repeat-domain-containing 7), a recognized developmental regulator and tumor suppressor, has been shown to regulate cell-cycle progression and cell growth and survival by targeting substrates including CYCLIN E1/2 and NOTCH for degradation via the ubiquitin proteasome system. We used a genotype-first approach and global data-sharing platforms to identify 35 individuals harboring de novo and inherited FBXW7 germline monoallelic chromosomal deletions and nonsense, frameshift, splice-site, and missense variants associated with a neurodevelopmental syndrome. The FBXW7 neurodevelopmental syndrome is distinguished by global developmental delay, borderline to severe intellectual disability, hypotonia, and gastrointestinal issues. Brain imaging detailed variable underlying structural abnormalities affecting the cerebellum, corpus collosum, and white matter. A crystal-structure model of FBXW7 predicted that missense variants were clustered at the substrate-binding surface of the WD40 domain and that these might reduce FBXW7 substrate binding affinity. Expression of recombinant FBXW7 missense variants in cultured cells demonstrated impaired CYCLIN E1 and CYCLIN E2 turnover. Pan-neuronal knockdown of the Drosophila ortholog, archipelago, impaired learning and neuronal function. Collectively, the data presented herein provide compelling evidence of an F-Box protein-related, phenotypically variable neurodevelopmental disorder associated with monoallelic variants in FBXW7.