Spectrum of neurodevelopmental disease associated with the GNAO1 guanosine triphosphate–binding region

• Published in: Epilepsia (Copenhagen) Vol. 60; no. 3; pp. 406 - 418
• Main Authors: Kelly, McKenna, Park, Meredith, Mihalek, Ivana, Pérez‐Palma, Eduardo, Anselm, Irina, Briere, Lauren C., High, Frances A., Sweetser, David A., Allard, Patrick, Ashley, Euan A., Bacino, Carlos A., Baker, Eva, Barseghyan, Hayk, Batzli, Gabriel F., Behnam, Babak, Bellen, Hugo J., Bernstein, Jonathan A., Bican, Anna, Bostwick, Bret L., Brush, Matthew, Burke, Elizabeth A., Burrage, Lindsay C., Butte, Manish J., Clark, Gary D., Colley, Heather A., Cooper, Cynthia M., Davids, Mariska, Dell’Angelica, Esteban C., Dorrani, Naghmeh, Douine, Emilie D., Emrick, Lisa T., Fairbrother, Laura, Fernandez, Liliana, Ferreira, Carlos, Fieg, Elizabeth L., Fisher, Paul G., Friedman, Noah D., Gahl, William A., Gourdine, Jean‐Philippe F., Groden, Catherine A., Gropman, Andrea L., Haendel, Melissa, Hom, Jason, Howerton, Ellen M., Jamal, Fariha, Jiang, Yong‐hui, Johnston, Jean M., Jones, Angela L., Karaviti, Lefkothea, Koeller, David M., Kohane, Isaac S., Koziura, Mary, Lalani, Seema R., Lazar, Jozef, Levy, Shawn E., Lincoln, Sharyn A., Maas, Richard L., Macnamara, Ellen F., MacRae, Calum A., Maduro, Valerie V., Majcherska, Marta M., Malicdan, May Christine V., Mamounas, Laura A., Manolio, Teri A., Markello, Thomas C., Marom, Ronit, Martínez‐Agosto, Julian A., May, Thomas, Morimoto, Marie, Mulvihill, John J., Murphy, Jennifer L., Nelson, Stan F., Newman, John H., Novacic, Donna, Orange, Jordan S., Potocki, Lorraine, Reuter, Chloe M., Rives, Lynette, Robertson, Amy K., Rodan, Lance H., Sampson, Jacinda B., Samson, Susan L., Schoch, Kelly, Silverman, Edwin K., Sinsheimer, Janet S., Smith, Kevin S., Spillmann, Rebecca C., Stong, Nicholas, Sullivan, Jennifer A., Waggott, Daryl M., Walsh, Chris A., Wangler, Michael F., Ward, Patricia A., Waters, Katrina M., Westerfield, Monte, Wheeler, Matthew T., Wise, Anastasia L., Worthey, Elizabeth A., Yoon, Amanda J., Zastrow, Diane B.
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01.03.2019
• Subjects: Adolescent; Amino acids; Ataxia; Case-Control Studies; Child; Child, Preschool; Chorea; Convulsions & seizures; developmental and epileptic encephalopathy; Dyskinesia; Dystonia; Encephalopathy; Epilepsy; Epilepsy - genetics; Female; Genetic Association Studies; Genetic Predisposition to Disease - genetics; Genetic Variation - genetics; Genotypes; GNAO1; GTP-Binding Protein alpha Subunits, Gi-Go - genetics; Guanosine; Guanosine triphosphate; Humans; Male; Mosaicism; Movement disorders; Neurodevelopmental disorders; Neurodevelopmental Disorders - genetics; Pathogenicity; Phenotypes; Protein structure; Proteins; Seizures; Young Adult; GNAO1; developmental and epileptic encephalopathy; movement disorders; mosaicism
• ISSN: 0013-9580; 1528-1167; 1528-1167
• DOI: 10.1111/epi.14653

Summary Objective To characterize the phenotypic spectrum associated with GNAO1 variants and establish genotype‐protein structure‐phenotype relationships. Methods We evaluated the phenotypes of 14 patients with GNAO1 variants, analyzed their variants for potential pathogenicity, and mapped them, along with those in the literature, on a three‐dimensional structural protein model. Results The 14 patients in our cohort, including one sibling pair, had 13 distinct, heterozygous GNAO1 variants classified as pathogenic or likely pathogenic. We attributed the same variant in two siblings to parental mosaicism. Patients initially presented with seizures beginning in the first 3 months of life (8/14), developmental delay (4/14), hypotonia (1/14), or movement disorder (1/14). All patients had hypotonia and developmental delay ranging from mild to severe. Nine had epilepsy, and nine had movement disorders, including dystonia, ataxia, chorea, and dyskinesia. The 13 GNAO1 variants in our patients are predicted to result in amino acid substitutions or deletions in the GNAO1 guanosine triphosphate (GTP)‐binding region, analogous to those in previous publications. Patients with variants affecting amino acids 207‐221 had only movement disorder and hypotonia. Patients with variants affecting the C‐terminal region had the mildest phenotypes. Significance GNAO1 encephalopathy most frequently presents with seizures beginning in the first 3 months of life. Concurrent movement disorders are also a prominent feature in the spectrum of GNAO1 encephalopathy. All variants affected the GTP‐binding domain of GNAO1, highlighting the importance of this region for G‐protein signaling and neurodevelopment.