Stretch-activated ion channel TMEM63B associates with developmental and epileptic encephalopathies and progressive neurodegeneration

By converting physical forces into electrical signals or triggering intracellular cascades, stretch-activated ion channels allow the cell to respond to osmotic and mechanical stress. Knowledge of the pathophysiological mechanisms underlying associations of stretch-activated ion channels with human d...

Full description

Saved in:

Bibliographic Details
Published in:	American journal of human genetics Vol. 110; no. 8; pp. 1356 - 1376
Main Authors:	Vetro, Annalisa, Pelorosso, Cristiana, Balestrini, Simona, Masi, Alessio, Hambleton, Sophie, Argilli, Emanuela, Giubbolini, Simone, Barrick, Rebekah, Bergant, Gaber, Writzl, Karin, Bijlsma, Emilia K., Cacheiro, Pilar, Mei, Davide, Devlin, Anita, Machol, Keren, Mannaioni, Guido, Sakamoto, Masamune, Menezes, Manoj P., Courtin, Thomas, Sherr, Elliott, Parra, Riccardo, Richardson, Ruth, Roscioli, Tony, Scala, Marcello, von Stülpnagel, Celina, Smedley, Damian, Pochiero, Francesca, Ramesh, Venkateswaran, Capra, Valeria, Mancardi, Margherita, Keren, Boris, Mignot, Cyiril, Lulli, Matteo, Parks, Kendall, Griffin, Helen, Nigro, Vincenzo, Hirata, Yuko, Koichihara, Reiko, Peterlin, Borut, Maki, Ryuto, Nitta, Yohei, Ambrose, John C., Arumugam, Prabhu, Bevers, Roel, Bleda, Marta, Boustred, Christopher R., Brittain, Helen, Brown, Matthew A., Caulfield, Mark J., Chan, Georgia C., Giess, Adam, Griffin, John N., Hamblin, Angela, Henderson, Shirley, Hubbard, Tim J.P., Jackson, Rob, Jones, Louise J., Kasperaviciute, Dalia, Kayikci, Melis, Kousathanas, Athanasios, Lahnstein, Lea, Lakey, Anna, Lopez, Javier F., Maleady-Crowe, Fiona, Minneci, Federico, Mueller, Michael, Murugaesu, Nirupa, Need, Anna C., O’Donovan, Peter, Odhams, Chris A., Patch, Christine, Rahim, Tahrima, Rendon, Augusto, Sawant, Kushmita, Siddiq, Afshan, Sieghart, Alexander, Smith, Samuel C., Stuckey, Alexander, Tanguy, Mélanie, Taylor Tavares, Ana Lisa, Thomas, Ellen R.A., Tucci, Arianna, Welland, Matthew J., Williams, Eleanor, Witkowska, Katarzyna, Wood, Suzanne M., Zarowiecki, Magdalena, Torella, Annalaura, Tohyama, Jun, Hamada, Keisuke, Ogata, Kazuhiro, Sugie, Atsushi, van der Smagt, Jasper J., van Gassen, Koen, Valence, Stephanie, Vittery, Emma, Malone, Stephen, Kato, Mitsuhiro, Ratto, Gian Michele, Guerrini, Renzo
Format:	Journal Article
Language:	English
Published:	United States Elsevier Inc 03-08-2023 Elsevier
Subjects:	abnormal myelination Brain Brain Diseases - genetics epilepsy epileptic encephalopathy hemolytic anemia Humans infantile spasms Intellectual Disability - genetics ion channels Ion Channels - genetics leak cation currents osmotic stress Phenotype white matter abnormality epilepsy osmotic stress white matter abnormality abnormal myelination leak cation currents infantile spasms ion channels epileptic encephalopathy hemolytic anemia
Online Access:	Get full text
Tags:	Add Tag No Tags, Be the first to tag this record!

Description
Summary:	By converting physical forces into electrical signals or triggering intracellular cascades, stretch-activated ion channels allow the cell to respond to osmotic and mechanical stress. Knowledge of the pathophysiological mechanisms underlying associations of stretch-activated ion channels with human disease is limited. Here, we describe 17 unrelated individuals with severe early-onset developmental and epileptic encephalopathy (DEE), intellectual disability, and severe motor and cortical visual impairment associated with progressive neurodegenerative brain changes carrying ten distinct heterozygous variants of TMEM63B, encoding for a highly conserved stretch-activated ion channel. The variants occurred de novo in 16/17 individuals for whom parental DNA was available and either missense, including the recurrent p.Val44Met in 7/17 individuals, or in-frame, all affecting conserved residues located in transmembrane regions of the protein. In 12 individuals, hematological abnormalities co-occurred, such as macrocytosis and hemolysis, requiring blood transfusions in some. We modeled six variants (p.Val44Met, p.Arg433His, p.Thr481Asn, p.Gly580Ser, p.Arg660Thr, and p.Phe697Leu), each affecting a distinct transmembrane domain of the channel, in transfected Neuro2a cells and demonstrated inward leak cation currents across the mutated channel even in isotonic conditions, while the response to hypo-osmotic challenge was impaired, as were the Ca2+ transients generated under hypo-osmotic stimulation. Ectopic expression of the p.Val44Met and p.Gly580Cys variants in Drosophila resulted in early death. TMEM63B-associated DEE represents a recognizable clinicopathological entity in which altered cation conductivity results in a severe neurological phenotype with progressive brain damage and early-onset epilepsy associated with hematological abnormalities in most individuals. [Display omitted] Combining in silico evaluation, in vitro electrophysiology and Ca2+ imaging, and in vivo modeling in Drosophila, Vetro et al. demonstrate that gain-of-function variants of the stretch-activated ion channel TMEM63B cause a severe neurodevelopmental disorder with early-onset epilepsy and progressive brain damage associated with hematological abnormalities in most individuals.
Bibliography:	ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 These authors contributed equally
ISSN:	0002-9297 1537-6605
DOI:	10.1016/j.ajhg.2023.06.008