1. BICRA, a SWI/SNF Complex Member, Is Associated with BAF-Disorder Related Phenotypes in Humans and Model Organisms
- Author
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Erin Conboy, Catherine Nowak, Karen Stals, Elliot S. Stolerman, Brett Bostwick, Tiana M. Scott, Emma Wakeling, Cyril Mignot, Sian Ellard, Brittany C. Michel, Kayla Treat, Berrak Ugur, Jill A. Rosenfeld, Caroline Nava, Sally Ann Lynch, Victoria M. Pratt, Hugo J. Bellen, Aiko Otsubo, Michael F. Wangler, Jennifer Gass, John Herriges, Jennifer B. Phillips, Gaetan Lesca, Bo Yuan, Shinya Yamamoto, Scott Barish, Marjon van Slegtenhorst, Jessica Douglas, Dihong Zhou, Patrick Edery, David R. Murdock, Jeremy Wegner, Jose Camacho, Marie Faoucher, Boris Keren, Camerun Washington, Elena Perenthaler, Kendra Engleman, Francesco Vetrini, Anita Nikoncuk, Alfredo M. Valencia, Daryl A. Scott, Cigall Kadoch, Isabelle Thiffault, Tahsin Stefan Barakat, Chun-An Chen, Lance H. Rodan, Raymond J. Louie, Hongzheng Dai, Alice S. Brooks, Nazar Mashtalir, Monte Westerfield, Nora Shannon, and Clinical Genetics
- Subjects
Male ,Adolescent ,Chromosomal Proteins, Non-Histone ,Developmental Disabilities ,Mutation, Missense ,Haploinsufficiency ,Article ,Chromatin remodeling ,03 medical and health sciences ,0302 clinical medicine ,Genetics ,Animals ,Drosophila Proteins ,Humans ,Missense mutation ,Child ,Zebrafish ,Genetics (clinical) ,Genes, Dominant ,030304 developmental biology ,Neurons ,0303 health sciences ,Microscopy, Confocal ,biology ,SWI/SNF complex ,Coarse facial features ,Tumor Suppressor Proteins ,Genetic Variation ,Infant ,Zebrafish Proteins ,Position-effect variegation ,biology.organism_classification ,Phenotype ,Drosophila melanogaster ,Child, Preschool ,Female ,Neuroglia ,030217 neurology & neurosurgery ,Protein Binding - Abstract
SWI/SNF-related intellectual disability disorders (SSRIDDs) are rare neurodevelopmental disorders characterized by developmental disability, coarse facial features, and fifth digit/nail hypoplasia that are caused by pathogenic variants in genes that encode for members of the SWI/SNF (or BAF) family of chromatin remodeling complexes. We have identified 12 individuals with rare variants (10 loss-of-function, 2 missense) in the BICRA (BRD4 interacting chromatin remodeling complex-associated protein) gene, also known as GLTSCR1, which encodes a subunit of the non-canonical BAF (ncBAF) complex. These individuals exhibited neurodevelopmental phenotypes that include developmental delay, intellectual disability, autism spectrum disorder, and behavioral abnormalities as well as dysmorphic features. Notably, the majority of individuals lack the fifth digit/nail hypoplasia phenotype, a hallmark of most SSRIDDs. To confirm the role of BICRA in the development of these phenotypes, we performed functional characterization of the zebrafish and Drosophila orthologs of BICRA. In zebrafish, a mutation of bicra that mimics one of the loss-of-function variants leads to craniofacial defects possibly akin to the dysmorphic facial features seen in individuals harboring putatively pathogenic BICRA variants. We further show that Bicra physically binds to other non-canonical ncBAF complex members, including the BRD9/7 ortholog, CG7154, and is the defining member of the ncBAF complex in flies. Like other SWI/SNF complex members, loss of Bicra function in flies acts as a dominant enhancer of position effect variegation but in a more context-specific manner. We conclude that haploinsufficiency of BICRA leads to a unique SSRIDD in humans whose phenotypes overlap with those previously reported.
- Published
- 2020