ANK2 loss-of-function variants are associated with epilepsy, and lead to impaired axon initial segment plasticity and hyperactive network activity in hiPSC-derived neuronal networks

Maria W. A. Teunissen (1, 2) , Elly Lewerissa (3) , Eline J. H. van Hugte (3) , Shan Wang (3) , Charlotte W. Ockeloen (4) , David A. Koolen (3) , Rolph Pfundt (4) , Carlo L. M. Marcelis (4) , Eva Brilstra (5) , Jennifer L. Howe (6) , Stephen W. Scherer (6, 7, 8) , Xavier Le Guillou (9) , Frédéric Bilan (10, 9) , Michelle Primiano (11) , Jasmin Roohi (11, 12) , Amélie Piton (13, 14) , Anne de Saint Martin (13, 14, 15) , Sarah Baer (13, 14, 15) , Simone Seiffert (16) , Konrad Platzer , Rami Abou Jamra , Steffen Syrbe (17) , Jan H Doering (17) , Shenela Lakhani (18) , Srishti Nangia (11) , Christian Gilissen (4) , R. Jeroen Vermeulen (1) , Rob P. W. Rouhl (1, 3, 19) , Han G. Brunner (19, 1, 4) , Marjolein H. Willemsen (4) , Nael Nadif Kasri (3)

1 MUMC - Maastricht University Medical Centre
2 Academic Center for Epileptology Kempenhaeghe & Maastricht UMC+ [Heeze]
3 Donders Institute for Brain, Cognition and Behaviour
4 Radboud University Medical Center [Nijmegen]
5 University Medical Center [Utrecht]
6 SickKids - The Hospital for sick children [Toronto]
7 University of Toronto McLaughlin Centre
8 University of Toronto
9 CHU de Poitiers [La Milétrie] - Centre hospitalier universitaire de Poitiers = Poitiers University Hospital
10 LNEC [Poitiers] - Laboratoire de neurosciences expérimentales et cliniques
11 New York Presbyterian Hospital
12 Kaiser Permanente
13 IGBMC - Institut de Génétique et de Biologie Moléculaire et Cellulaire
14 Institute of Genetics [Illkirch]
15 Hôpital de Hautepierre [Strasbourg]
16 Hertie Institute for Clinical Brain Research [Tubingen]
17 Heidelberg University Hospital [Heidelberg]
18 Center for neurogenetics [Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York]
19 Maastricht University [Maastricht]

PURPOSE: To characterize a novel neurodevelopmental syndrome due to loss-of-function (LoF) variants in Ankyrin 2 (ANK2), and to explore the effects on neuronal network dynamics and homeostatic plasticity in human-induced pluripotent stem cell-derived neurons. METHODS: We collected clinical and molecular data of 12 individuals with heterozygous de novo LoF variants in ANK2. We generated a heterozygous LoF allele of ANK2 using CRISPR/Cas9 in human-induced pluripotent stem cells (hiPSCs). HiPSCs were differentiated into excitatory neurons, and we measured their spontaneous electrophysiological responses using micro-electrode arrays (MEAs). We also characterized their somatodendritic morphology and axon initial segment (AIS) structure and plasticity. RESULTS: We found a broad neurodevelopmental disorder (NDD), comprising intellectual disabi ity, autism spectrum disorders and early onset epilepsy. Using MEAs, we found that hiPSC-derived neurons with heterozygous LoF of ANK2 show a hyperactive and desynchronized neuronal network. ANK2-deficient neurons also showed increased somatodendritic structures and altered AIS structure of which its plasticity is impaired upon activity-dependent modulation. CONCLUSIONS: Phenotypic characterization of patients with de novo ANK2 LoF variants defines a novel NDD with early onset epilepsy. Our functional in vitro data of ANK2-deficient human neurons show a specific neuronal phenotype in which reduced ANKB expression leads to hyperactive and desynchronized neuronal network activity, increased somatodendritic complexity and AIS structure and impaired activity-dependent plasticity of the AIS.

Domaines: Neurosciences [q-bio.NC]; Génétique humaine; Médecine humaine et pathologie

Maria W. A. Teunissen, Elly Lewerissa, Eline J. H. van Hugte, Shan Wang, Charlotte W. Ockeloen, et al.. ANK2 loss-of-function variants are associated with epilepsy, and lead to impaired axon initial segment plasticity and hyperactive network activity in hiPSC-derived neuronal networks. Human Molecular Genetics, 2023, 32 (14), pp.2373-2385. ⟨10.1093/hmg/ddad081⟩. ⟨hal-04456350⟩