Expansion of the neurodevelopmental phenotype of individuals with EEF1A2 variants and genotype-phenotype study

Alix Paulet (Lead / Corresponding author), Cavan Bennett-Ness, Faustine Ageorges, Detlef Trost, Andrew Green, David Goudie, Rosalyn Jewell, Minna Kraatari-Tiri, Juliette Piard, Christine Coubes, Wayne Lam, Sally Ann Lynch, Groeschel Samuel, Francis Ramond, Joël Fluss, Christina Fagerberg, Charlotte Brasch Andersen, Konstantinos Varvagiannis, Tjitske Kleefstra, Bénédicte GérardMélanie Fradin, Antonio Vitobello, Romano Tenconi, Anne-Sophie Denommé-Pichon, Aline Vincent-Devulder, Tobias Haack, Joseph A Marsh, Lone Walentin Laulund, Mona Grimmel, Angelika Riess, Elke de Boer, Sergio Padilla-Lopez, Somayeh Bakhtiari, Michael C Kruer, Jonathan Levy, Alain Verloes, Catherine M Abbott, Lyse Ruaud

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


Translation elongation factor eEF1A2 constitutes the alpha subunit of the elongation factor-1 complex, responsible for the enzymatic binding of aminoacyl-tRNA to the ribosome. Since 2012, 21 pathogenic missense variants affecting EEF1A2 have been described in 42 individuals with a severe neurodevelopmental phenotype including epileptic encephalopathy and moderate to profound intellectual disability (ID), with neurological regression in some patients. Through international collaborative call, we collected 26 patients with EEF1A2 variants and compared them to the literature. Our cohort shows a significantly milder phenotype. 83% of the patients are walking (vs. 29% in the literature), and 84% of the patients have language skills (vs. 15%). Three of our patients do not have ID. Epilepsy is present in 63% (vs. 93%). Neurological examination shows a less severe phenotype with significantly less hypotonia (58% vs. 96%), and pyramidal signs (24% vs. 68%). Cognitive regression was noted in 4% (vs. 56% in the literature). Among individuals over 10 years, 56% disclosed neurocognitive regression, with a mean age of onset at 2 years. We describe 8 novel missense variants of EEF1A2. Modeling of the different amino-acid sites shows that the variants associated with a severe phenotype, and the majority of those associated with a moderate phenotype, cluster within the switch II region of the protein and thus may affect GTP exchange. In contrast, variants associated with milder phenotypes may impact secondary functions such as actin binding. We report the largest cohort of individuals with EEF1A2 variants thus far, allowing us to expand the phenotype spectrum and reveal genotype-phenotype correlations.

Original languageEnglish
Number of pages6
JournalEuropean Journal of Human Genetics
Early online date15 Feb 2024
Publication statusE-pub ahead of print - 15 Feb 2024


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