There are so many people to thank including @leastarita.bsky.social and @dougfowler.bsky.social for their amazing mentorship as well as: @riddhiman.bsky.social , @treependyala.bsky.social , @caseygifford.bsky.social , @sudpinglay.bsky.social and other co-authors not on Bluesky.

We highlight the power of iPSC-SGE by identifying sarcomere dependent variant effects of MYBPC3 in cardiomyocytes. Additionally, we identified dominant negative and LOF variant effects in POLG by assaying variants in multiple genetic backgrounds. Please see our preprint for more exciting results!

In iPSC-SGE, we first had to overcome challenges of genome editing in stem cells. To do this, we edit both the background and SNV containing alleles with large repair templates replacing endogenous gene segments while adding markers and reporters and introduced over 1,500 SNVs in MYBPC3 and POLG.

VUS remain a large and growing problem for clinical genetics and iPSC-SGE is critical to solving this problem. While assays targeting genes that are essential to cancer derived HAP1 cells have been effective at resolving VUS, only ~15% of VUS currently in ClinVar occur within these genes.

Editing stem cell genomes at scale to measure variant effects in diverse cell and genetic contexts Multiplexed assays of variant effect (MAVEs) systematically measure variant function but have been limited to cancer cell lines rather than disease-relevant cell types. We developed saturation genome ...

The effects of genetic variants primarily occur in differentiated cells meaning we need to access these cell types to measure variant effects for most disease genes. We developed saturation genome editing in stem cells (iPSC-SGE) to enable phenotyping in diverse genetic and cell contexts at scale!

Theodore Ciabatta*