Maxwell Sherman’s paper on mosaic CNVs in autism (Sherman et al. 2020 Nat Neurosci) is now published — congratulations, Max! This work, a collaboration with Chris Walsh and Peter Park, implicated large mosaic copy number variants (CNVs) arising early in embryonic development as a likely contributor to sporadic cases of autism spectrum disorder (ASD) in the Simons Simplex Collection (SSC) and SPARK data sets. Interestingly, unlike the recurrent, short germline CNVs (e.g., at 16p11.2 and 22q11.2) previously implicated in ASD, the mosaic CNVs that associated with ASD tended to be large (>4 Mb) and spread across the genome, suggesting that that these mutations may confer pathogenicity by disrupting many genes rather than specific, focal loci. [Nat Rev Genet highlight | BCH news story | Spectrum news story]