Chd7-KO transcriptomic analysis. Chd7-KO transcriptomic analysis

Mutations in the chromatin remodeller CHD7 cause CHARGE syndrome (CS). Importantly, children with CS exhibit moderate to severe neurological and behaviour symptoms including autism. However, the neural substrates underlying these symptoms remain largely unknown. Here we show that zebrafish chd7 mutant display a nighttime hyperactivity behavioural phenotype and exhibit altered number and positioning of GABAergic neurons in brain regions. Using a transcriptomic approach, we identified many genes involved in cell adhesion, migration and receptor signalling that are dysregulated in the chd7 brain. We also show an abnomal hyperactivation of ERK signalling contributing to the GABAergic defects. A phenotype-based screen of 3850 compounds identifies a lead compound, ephedrine that ameliorates GABAergic and behavioural anomalies in chd7 animals. Our study identifies CHD7 as critical regulator of GABAergic network development. Importantly, we provide novel insight into the mechanisms underlying the neurological deficits in CS and identify a new therapeutic for CS-associated neurobehavioural symptoms. Overall design: 5 dpf dissected larval brains