Sasha Gusev
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sashagusevposts.bsky.social
Sasha Gusev
@sashagusevposts.bsky.social
Statistical geneticist. Associate Prof at Dana-Farber / Harvard Medical School.

www.gusevlab.org
GAZZILLION EAR (THOM YORKE Remix)
YouTube video by MF DOOM - Topic
www.youtube.com
October 20, 2025 at 2:26 AM
Yeah I don't really get it. The hard part is getting the genetic estimates so running this across many other 23andme traits (even restricting to non-controversial traits) would have been very informative. Perhaps they're going to follow up with more detailed linkage analyses?
September 20, 2025 at 6:50 PM
You can estimate the total genetic difference between populations without having to know the underlying causal variants. You don't get the mechanism and you still have to make strong assumptions on GxE and ascertainment, but IMO an effective way to prioritize traits for follow-up.
September 17, 2025 at 2:36 PM
Yes, exactly, the idea was to overload the cells with many perturbations and then estimate components of higher-order interactions GREML-like. But we couldn't get enough cells with multiple edits and only had power to look at module interactions.

www.nature.com/articles/s41...
Scalable genetic screening for regulatory circuits using compressed Perturb-seq - Nature Biotechnology
Compressed Perturb-seq incorporates compressed sensing to genetic screening for scalable discovery of genetic interactions.
www.nature.com
September 9, 2025 at 9:24 PM
We were hoping to look at this in perturb-seq data, but very hard to get the number of combinatorial effects needed for statistical power.
September 9, 2025 at 8:09 PM
I think about this every time I shave:
September 3, 2025 at 3:50 AM
very relevant, thank you!
August 31, 2025 at 12:38 AM
That's a great idea, and looks something like the below. I'm working on the size scaling a bit more to convey the point more clearly
August 29, 2025 at 12:37 AM
Yeah I was thinking about this initially and unable to find any examples in the literature where epistasis tagged by additivity versus "pure" additivity mattered. I think the response really is just about narrow-sense h2 (as in the Breeder's Equation).
August 29, 2025 at 12:35 AM
Reposted by Sasha Gusev
Nice blog and good to see this also from the twins/shared environment side. We (with my colleagues in @wittbrodtlab.bsky.social) have tried to tackle the non-additive in experimental settings (in medaka fish) which we can map to human (as the medaka fish are "wild") www.biorxiv.org/content/10.1...
Discovery and characterisation of gene by environment and epistatic genetic effects in a vertebrate model
Phenotypic variation arises from the interplay between genetic and environmental factors. However, disentangling these interactions for complex traits remains challenging in observational cohorts such...
www.biorxiv.org
August 28, 2025 at 3:10 PM
Yeah, uncentered effects make more sense to me biologically but of course you could design a statistical generative model where the interaction is purely non-additive.
August 29, 2025 at 12:07 AM
great commentary article (and thanks for the thread!)
August 28, 2025 at 1:47 PM
Yeah, in general multi component models will only take the part of the interaction that is not captured by additivity. The twin ADE model partitions them correctly but ONLY if there's no shared environment (and other assumptions hold).
August 28, 2025 at 1:41 PM
Sure thing, see this gist. Note that this is always the affect allele frequency and not the minor allele frequency and there's no genotype scaling. Let me know if you think there's a better presentation.
simple epistasis model
simple epistasis model. GitHub Gist: instantly share code, notes, and snippets.
gist.github.com
August 28, 2025 at 1:52 AM