Partial Loss of USP9X Function Leads to a Male Neurodevelopmental and Behavioral Disorder Converging on Transforming Growth Factor β Signaling

Brett V. Johnson, Raman Kumar, Sabrina Oishi, Suzy Alexander, Maria Kasherman, Michelle Sanchez Vega, Atma Ivancevic, Alison Gardner, Deepti Domingo, Mark Corbett, Euan Parnell, Sehyoun Yoon, Tracey Oh, Matthew Lines, Henrietta Lefroy, Usha Kini, Margot van Allen, Sabine Grønborg, Sandra Mercier, S. bastien KüryStéphane Bézieau, Laurent Pasquier, Martine Raynaud, Alexandra Afenjar, Thierry Billette de Villemeur, Boris Keren, Julie Désir, Lionel van Maldergem, Martina Marangoni, Nicola Dikow, David A. Koolen, Peter M. VanHasselt, Marjan Weiss, Petra Zwijnenburg, Joaquim Sa, Claudia Falcao Reis, Carlos López-Otín, Olaya Santiago-Fernández, Alberto Fernández-Jaén, Anita Rauch, Katharina Steindl, Pascal Joset, Amy Goldstein, Suneeta Madan-Khetarpal, Elena Infante, Elaine Zackai, Carey Mcdougall, Vinodh Narayanan, Keri Ramsey, Undiagnosed Diseases Network, Mariska Davids, Jennifer A. Sullivan, Margaret Au, Luis A. Pérez-Jurado, Tjitske Kleefstra, Peter Penzes, Stephen A. Wood, Thomas Burne, Tyler Pierson, Michael Piper, Jozef Gecz, Lachlan A. Jolly

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

Background: The X-chromosome gene USP9X encodes a deubiquitylating enzyme that has been associated with neurodevelopmental disorders primarily in female subjects. USP9X escapes X inactivation, and in female subjects de novo heterozygous copy number loss or truncating mutations cause haploinsufficiency culminating in a recognizable syndrome with intellectual disability and signature brain and congenital abnormalities. In contrast, the involvement of USP9X in male neurodevelopmental disorders remains tentative. Methods: We used clinically recommended guidelines to collect and interrogate the pathogenicity of 44 USP9X variants associated with neurodevelopmental disorders in males. Functional studies in patient-derived cell lines and mice were used to determine mechanisms of pathology. Results: Twelve missense variants showed strong evidence of pathogenicity. We define a characteristic phenotype of the central nervous system (white matter disturbances, thin corpus callosum, and widened ventricles); global delay with significant alteration of speech, language, and behavior; hypotonia; joint hypermobility; visual system defects; and other common congenital and dysmorphic features. Comparison of in silico and phenotypical features align additional variants of unknown significance with likely pathogenicity. In support of partial loss-of-function mechanisms, using patient-derived cell lines, we show loss of only specific USP9X substrates that regulate neurodevelopmental signaling pathways and a united defect in transforming growth factor β signaling. In addition, we find correlates of the male phenotype in Usp9x brain-specific knockout mice, and further resolve loss of hippocampal-dependent learning and memory. Conclusions: Our data demonstrate the involvement of USP9X variants in a distinctive neurodevelopmental and behavioral syndrome in male subjects and identify plausible mechanisms of pathogenesis centered on disrupted transforming growth factor β signaling and hippocampal function.
Original languageEnglish
Pages (from-to)100-112
JournalBiological Psychiatry
Volume87
Issue number2
DOIs
Publication statusPublished - 15 Jan 2020

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