Dominant β-catenin mutations cause intellectual disability with recognizable syndromic features

Valter Tucci, Tjitske Kleefstra, Andrea Hardy, Ines Heise, Silvia Maggi, Marjolein H. Willemsen, Helen Hilton, Chris Esapa, Michelle Simon, Maria-Teresa Buenavista, Liam J. McGuffin, Lucie Vizor (+24 others)
2014 Journal of Clinical Investigation  
The recent identification of multiple dominant mutations in the gene encoding β-catenin in both humans and mice has enabled exploration of the molecular and cellular basis of β-catenin function in cognitive impairment. In humans, β-catenin mutations that cause a spectrum of neurodevelopmental disorders have been identified. We identified de novo β-catenin mutations in patients with intellectual disability, carefully characterized their phenotypes, and were able to define a recognizable
more » ... ual disability syndrome. In parallel, characterization of a chemically mutagenized mouse line that displays features similar to those of human patients with β-catenin mutations enabled us to investigate the consequences of β-catenin dysfunction through development and into adulthood. The mouse mutant, designated batface (Bfc), carries a Thr653Lys substitution in the C-terminal armadillo repeat of β-catenin and displayed a reduced affinity for membrane-associated cadherins. In association with this decreased cadherin interaction, we found that the mutation results in decreased intrahemispheric connections, with deficits in dendritic branching, long-term potentiation, and cognitive function. Our study provides in vivo evidence that dominant mutations in β-catenin underlie losses in its adhesion-related functions, which leads to severe consequences, including intellectual disability, childhood hypotonia, progressive spasticity of lower limbs, and abnormal craniofacial features in adults.
doi:10.1172/jci70372 pmid:24614104 pmcid:PMC3973091 fatcat:mrbvshcojve6tkf5eocuc5ucay