Copy number variants (CNVs) – intervals of DNA in which one genomic copy is duplicated or deleted – are associated with many different human disorders. CNVs of 16p11.2 are associated with problems including intellectual disability disorder (IDD) and autism spectrum disorders (ASDs). The 16p11.2 interval contains 25 genes, but which genes are important for its association with brain disorders is unclear. Blaker-Lee, Gupta, McCammon et al. identified zebrafish homologs of 22 of these genes, 20 of which were important for normal brain development. Two genes – encoding glycolytic enzyme aldolase A (Aldoa) and microtubule motor kinesin family member 22 (Kif22) – caused a phenotype at 50% expression levels, suggesting that their function is dosage-sensitive. These data will guide future studies of the association between 16p11.2 and brain disorders in mammals, and indicate that zebrafish are an effective tool for investigating other disease-associated CNVs. Page 834

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial Share Alike License (, which permits unrestricted non-commercial use, distribution and reproduction in any medium provided that the original work is properly cited and all further distributions of the work or adaptation are subject to the same Creative Commons License terms.