De novo EHMT2 variants cause an autosomal dominant EHMT2-related Kleefstra syndrome via loss of G9a methyltransferase activity
Abstract
Abstract EHMT1 and EHMT2 genes encode human euchromatin histone lysine methyltransferase 1 and 2 (EHMT1 alias GLP; EHMT2 alias G9a) that form heteromeric GLP/G9a complexes with essential roles in epigenetic regulation of gene expression. While EHMT1 haploinsufficiency has been established as the cause of Kleefstra syndrome 1, the pathogenesis of G9a dysfunction in human disease remains largely unknown. We identified seven de novo EHMT2 variants in patients with clinical presentation, episignatures, histone modifications and transcriptomic profiles similar to those of Kleefstra syndrome 1. In vitro studies reveal that these variants encode for structurally stable G9a proteins that are catalytically incompetent due to aberrant interactions either with histone H3 tail or with S-adenosylmethionine. Heterozygous mice carrying a patient-derived variant exhibit growth retardation, facial/skull dysmorphia and aberrant behavior. Here we report pathogenic EHMT2 variants that likely exert dominant-negative effect on GLP/G9a complexes and thus genocopy the EHMT1 haploinsufficiency via a distinct molecular mechanism, defining an autosomal dominant EHMT2 -related Kleefstra syndrome.
Article Details
Authors (70)
Aleš Hnízda
Beatriz Martinez-Delgado
Diana Sánchez-Ponce
Javier Alonso
Jeanne Amiel
Tania Attie-Bitach
Ariadna Bada-Navarro
Beatriz Baladron
Eva Bermejo-Sanchez
Vítězslav Brinsa
Ivana Buková
Rosario Cazorla-Calleja
Sylvie Červenková
Shanshan Chow
Petr Dušek
Olha Fedosieieva
Marta Fernandez-Prieto
Sourav Ghosh
Gema Gomez-Mariano
Andrea Gřegořová
Mark James Hamilton
Hana Hartmannová
Esther Hernandez-SanMiguel
Marina Herrero-Matesanz
Kateřina Hodaňová
Alan Kádek
Jennifer Kerkhof
Tjitske Kleefstra
Didier Lacombe
Michael A. Levy
Estrella Lopez-Martin
Ruaud Lyse
Petr Man
Purificacion Marin-Reina
Ellen F. Macnamara
Haley McConkey
Petra Melenovská
Lidia M. Mielu
David Moore
Lenka Steiner Mrázová
Karolína Musilová
Kristýna Neffeová
Petr Nickl
David Pajuelo Reguera
Martina Pavlíková
Lea Pavlovičová
Manuel Posada
Jan Procházka
Kateryna Pysanenko
Sheila Ramos del Saz
Dmitrijs Rots
Jessica Rzasa
Radislav Sedláček
Viktor Stránecký
František Špoutil
Matthew L. Tedder
Louise Thompson
Cynthia J. Tifft
Office of the Clinical Director, National Human Genome Research Institute, Bethesda, MD
Frederic Tran Mau-Them
Helena Trešlová
Antonio Vitobello
Sarah Hilton
Christopher Campbell
Siddharth Banka
Daniel Jirák
Bekim Sadikovic
Jakub Sikora
Stanislav Kmoch
Maria J. Barrero
Lenka Nosková