Seth D. Temple
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sdtemple.bsky.social
Seth D. Temple
@sdtemple.bsky.social
PhD Statistician (github.com/sdtemple)
UMich & UWashington Stats
Overall, the method is a scalable and interpretable way to look for haplotype homozygosity in biobanks. I have spent a lot of time implementing it to make it user friendly. Running this can be important to check for confounding: see our other preprint.
pubmed.ncbi.nlm.nih.gov/40672175/
Multiple-testing corrections in case-control studies using identity-by-descent segments - PubMed
Identity-by-descent (IBD) mapping provides complementary signals to genome-wide association studies (GWAS) when multiple causal haplotypes or variants are present, but not directly tested. However, fa...
pubmed.ncbi.nlm.nih.gov
September 26, 2025 at 4:29 PM
While we have improved (made a more conservative threshold for the African American analysis), there are still unmodeled complexities and likely fine-scale structure that violates our assumption. Buyer beware if signal is weak (barely GW significant)!
September 26, 2025 at 4:29 PM
We filter to have small admixture proportions in our African American analysis. We think that admixture is more likely to deflate our "selection signal", not inflate it. This is a robustness check.
September 26, 2025 at 4:29 PM
We think that low-mappability, problematic regions are more likely to deflate our "selection" signal, not inflate it. See Appendix B. This is a robustness check.
September 26, 2025 at 4:29 PM
There is a large signal of unusual haplotype structure at a chr16 locus in all groups. I also see this when analyzing other consortia data. We describe it in more detail as a complicated region enriched with deletions. Gusev et al have also reported on it.
academic.oup.com/mbe/article/...
The Architecture of Long-Range Haplotypes Shared within and across Populations
Abstract. Homologous long segments along the genomes of close or remote relatives that are identical by descent (IBD) from a common ancestor provide clues
academic.oup.com
September 26, 2025 at 4:29 PM
This is a new conceptual figure which explains how to make our proofs. I hope this idea is helpful to other population geneticists.
July 16, 2025 at 3:33 PM
This project completes my development of our suite of methods called isweep, which can detect recent selection and case-control associations, can narrow in on the selection signal, and has fast local simulations to perform statistical inference.
July 7, 2025 at 10:34 PM
You can also run a fast scan with randomized phenotypes to double check if selection is confounding.
July 7, 2025 at 10:34 PM
Sadly, the test is prone to confounding due to very strong positive and recent selection (see LCT in European ancestry cohorts). You can automatically check for this as a part of the automated workflow.
July 7, 2025 at 10:34 PM
Two of the six genome-wide significant signals are about current therapeutic targets, e.g., at the NBAS gene.
July 7, 2025 at 10:34 PM
We ran the scalable scan for three ancestry cohorts (European, African, and Amish) in the Alzheimer's Disease Sequencing Project.
July 7, 2025 at 10:34 PM
The null model is again motivated by the Temple and Thompson (2025) central limit theorems, which is now published in Theoretical Population Biology.
July 7, 2025 at 10:34 PM
The test is a two-sample modification of the one-sample selection scan from my prior work (Temple and Browning, 2025): high IBD rates differences in cases versus controls could indicate a genetic association.
July 7, 2025 at 10:34 PM
We discuss the use cases of local versus genome-wide IBD simulation. I'll say I have had a great time using msprime + tskibd for genome-wide simulations. We find it is accurate w.r.t. to our work. I highly recommend it.
github.com/bguo068/tskibd
GitHub - bguo068/tskibd: Calculate IBD segments from tree sequence using tskit C API
Calculate IBD segments from tree sequence using tskit C API - bguo068/tskibd
github.com
June 2, 2025 at 4:57 PM
One fantastic suggestion from both peer reviewers was to validate the accuracy of IBD segment length distributions w.r.t. existing tools. These studies are now included as Figures S7-10.
June 2, 2025 at 4:57 PM
Correction: 3) should be approx. has the first-order Markov property. This is what I get for tweeting fast.
January 30, 2025 at 9:35 PM