1. Novel missense mutations in PTCHD1 alter its plasma membrane subcellular localization and cause intellectual disability and autism spectrum disorder
- Author
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Sylviane Marouillat, Marie-Laure Vuillaume, Thomas Smol, Rose-Anne Thépault, Lyse Ruaud, Sarah Grotto, Jamal Ghoumid, Nicolas Chatron, Annick Toutain, Marianne Till, Alain Verloes, Manon Dixneuf, Valérie Chune, Gaetan Lesca, Frédéric Laumonnier, Nathalie Couque, Bénédicte Gérard, Martine Raynaud, Judith Halewa, Dévina C. Ung, Imagerie et cerveau (iBrain - Inserm U1253 - UNIV Tours ), Université de Tours (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM), Hospices Civils de Lyon (HCL), Institut NeuroMyoGène (INMG), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Les Hôpitaux Universitaires de Strasbourg (HUS), Maladies RAres du DEveloppement embryonnaire et du MEtabolisme : du Phénotype au Génotype et à la Fonction - ULR 7364 (RADEME), Université de Lille-Centre Hospitalier Régional Universitaire [Lille] (CHRU Lille), Hôpital Robert Debré, Maladies neurodéveloppementales et neurovasculaires (NeuroDiderot (UMR_S_1141 / U1141)), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Paris Cité (UPCité), Service de génétique [Tours], Centre Hospitalier Régional Universitaire de Tours (CHRU Tours)-Hôpital Bretonneau, ANR-20-CE17-0006,ASDecode,Approches translationnelles pour la caractérisation de la voie PTCHD1 impliquée dans les troubles neurodéveloppementaux(2020), Laumonnier, Frédéric, Approches translationnelles pour la caractérisation de la voie PTCHD1 impliquée dans les troubles neurodéveloppementaux - - ASDecode2020 - ANR-20-CE17-0006 - AAPG2020 - VALID, Université de Tours-Institut National de la Santé et de la Recherche Médicale (INSERM), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Paris (UP), and Hôpital Bretonneau-Centre Hospitalier Régional Universitaire de Tours (CHRU Tours)
- Subjects
Male ,[SDV]Life Sciences [q-bio] ,Mutation, Missense ,autism spectrum disorder ,Biology ,[SDV.GEN.GH] Life Sciences [q-bio]/Genetics/Human genetics ,functional analyses ,PTCHD1 (patched domain containing 1) gene ,03 medical and health sciences ,Mice ,in vitro cellular models ,subcellular localization ,Genetics ,medicine ,Missense mutation ,Animals ,Humans ,Gene ,Genetics (clinical) ,Research Articles ,030304 developmental biology ,chemistry.chemical_classification ,0303 health sciences ,Endoplasmic reticulum ,030305 genetics & heredity ,Cell Membrane ,Membrane Proteins ,Subcellular localization ,medicine.disease ,In vitro ,Transmembrane protein ,Amino acid ,[SDV] Life Sciences [q-bio] ,chemistry ,[SDV.GEN.GH]Life Sciences [q-bio]/Genetics/Human genetics ,Autism spectrum disorder ,intellectual disability ,missense variants ,Research Article - Abstract
The X‐linked PTCHD1 gene, encoding a synaptic membrane protein, has been involved in neurodevelopmental disorders with the description of deleterious genomic microdeletions or truncating coding mutations. Missense variants were also identified, however, without any functional evidence supporting their pathogenicity level. We investigated 13 missense variants of PTCHD1, including eight previously described (c.152G>A,p.(Ser51Asn); c.217C>T,p.(Leu73Phe); c.517A>G,p.(Ile173Val); c.542A>C,p.(Lys181Thr); c.583G>A,p.(Val195Ile); c.1076A>G,p.(His359Arg); c.1409C>A,p.(Ala470Asp); c.1436A>G,p.(Glu479Gly)), and five novel ones (c.95C>T,p.(Pro32Leu); c.95C>G,p.(Pro32Arg); c.638A>G,p.(Tyr213Cys); c.898G>C,p.(Gly300Arg); c.928G>C,p.(Ala310Pro)) identified in male patients with intellectual disability (ID) and/or autism spectrum disorder (ASD). Interestingly, several of these variants involve amino acids localized in structural domains such as transmembrane segments. To evaluate their potentially deleterious impact on PTCHD1 protein function, we performed in vitro overexpression experiments of the wild‐type and mutated forms of PTCHD1‐GFP in HEK 293T and in Neuro‐2a cell lines as well as in mouse hippocampal primary neuronal cultures. We found that six variants impaired the expression level of the PTCHD1 protein, and were retained in the endoplasmic reticulum suggesting abnormal protein folding. Our functional analyses thus provided evidence of the pathogenic impact of missense variants in PTCHD1, which reinforces the involvement of the PTCHD1 gene in ID and in ASD., Thirteen missense variants in the PTCHD1 gene associated with X‐linked neurodevelopmental disorder were investigated to address their potentially deleterious impact. Their overexpression in various cell lines (HEK293T, Neuro‐2a) and in primary neuronal cultures revealed abnormal protein stability and impaired subcellular localization, thus providing further evidence for the significant impact of PTCHD1 genetic alterations in intellectual disability and in autism spectrum disorder.
- Published
- 2021
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