Rima Kochman1, Ibrahima Ba2,12, Maïlyn Yates3,12, Vithura Pirabakaran4,12, Florian Gourmelon5,12, Dmitri Churikov1,12, Marc Laffaille1, Laëtitia Kermasson4, Coline Hamelin1, Isabelle Marois3, Frédéric Jourquin1, Laura Braud1, Marianne Bechara5, Elodie Lainey6, Hilario Nunes7, Philippe Breton8, Morgane Penhouet9, Pierre David10, Vincent Géli1, Christophe Lachaud1, Alexandre Maréchal3, Patrick Revy4,13, Caroline Kannengiesser2,13, Carole Saintomé5,11,13 and Stéphane Coulon1,13 1UMR7258 Centre National de la Recherche Scientifique (CNRS), UMR1068 Institut National de la Santé et de la Recherche Médicale (INSERM), UM105 Aix Marseille University, Institut Paoli-Calmettes, Centre de Recherche en Cancérologie de Marseille (CRCM), Laboratoire Labellisée par la Ligue Nationale Contre le Cancer, F-13009 Marseille, France; 2U1152 INSERM, Department of Genetics, Assistance Publique-Hôpitaux de Paris, Bichat Hospital, Paris Cité University, F-75018 Paris, France; 3Department of Biology, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada; 4UMR1163 INSERM, Genome Dynamics in the Immune System Laboratory, Laboratoire labellisé Ligue 2023, Imagine Institute, Paris Cité University, F-75015 Paris, France; 5UMR7196 CNRS, U1154 INSERM, Structure et Instabilité des Génomes, Muséum National d'Histoire Naturelle, F-75005 Paris, France; 6Assistance Publique Hôpitaux de Paris, Service d'Hématologie, Hôpital Robert Debré, Groupe Hospitalier Universitaire (GHU) AP-HP Nord, Université Paris Cité, F-75019 Paris, France; 7Assistance Publique Hôpitaux de Paris, Service de Pneumologie, Hôpital Avicenne, F-93000 Bobigny, France; 8Centre Hospitalier Universitaire (CHU) Les Sables d'Olonne, Pôle santé Service Pneumologie, 85340 Olonne, France; 9CHU Nantes, Hôpital Nord Laënnec Service de Pneumologie, Unité de Transplantation Thoracique, F-44093 Nantes, France; 10UMR1163 INSERM, Imagine Institute, Université de Paris, Transgenesis Facility, F-75015 Paris, France; 11UFR927, Sorbonne Université, F-75005 Paris, France Corresponding author: stephane.couloninserm.fr

↵12 These authors contributed equally to this work.

↵13 These authors contributed equally to this work.

Abstract

Premature telomere shortening or telomere instability is associated with a group of rare and heterogeneous diseases collectively known as telomere biology disorders (TBDs). Here we identified two unrelated individuals with clinical manifestations of TBDs and short telomeres associated with the identical monoallelic variant c.767A>G; Y256C in RPA2. Although the replication protein A2 (RPA2) mutant did not affect ssDNA binding and G-quadruplex-unfolding properties of RPA, the mutation reduced the affinity of RPA2 with the ubiquitin ligase RFWD3 and reduced RPA ubiquitination. Using engineered knock-in cell lines, we found an accumulation of RPA at telomeres that did not trigger ATR activation but caused short and dysfunctional telomeres. Finally, both patients acquired, in a subset of blood cells, somatic genetic rescue events in either POT1 genes or TERT promoters known to counteract the accelerated telomere shortening. Collectively, our study indicates that variants in RPA2 represent a novel genetic cause of TBDs. Our results further support the fundamental role of the RPA complex in regulating telomere length and stability in humans.

Received June 18, 2024. Accepted August 18, 2024.