Shai Carmi's Avatar

Shai Carmi

@shaicarmi

Associate professor at the Hebrew University of Jerusalem. Statistical, population, and medical genetics; preimplantation genetic testing. Views my own. http://scarmilab.org

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26.10.2023
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Latest posts by Shai Carmi @shaicarmi

Example ChASM Analysis Using Example Data

Want to check your ancient DNA study for chromosomal aneuploidies? RChASM is now available for R, to screen for autosomal and sex chromosomal aneuploidies, such as Down syndrome on data from 0.0014X coverage.

We also wrote a step-by-step tutorial with examples:
jonotuke.github.io/RChASM/artic...

05.03.2026 05:20 πŸ‘ 8 πŸ” 7 πŸ’¬ 0 πŸ“Œ 0

Have you ever wondered how many archaic populations contributed DNA to modern humans? We know about Neanderthals and Denisovans, but the fossil and genetic evidence suggests a much more complex history!

www.biorxiv.org/content/10.6...

05.03.2026 18:17 πŸ‘ 28 πŸ” 16 πŸ’¬ 1 πŸ“Œ 4
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Should biology put complexity first? The dictum β€œEverything should be made as simple as possible, but no simpler” poses a problem for biology. How simply can it be told without doing dama…

Great perspective by @philipcball.bsky.social.

Elementary genetics teaching (HS/college) focuses on Mendelian traits (single gene => single trait). However, it is now clear that polygenicity and pleiotropy are the norm. Curriculum must change accordingly.

www.sciencedirect.com/science/arti...

01.03.2026 12:00 πŸ‘ 33 πŸ” 15 πŸ’¬ 0 πŸ“Œ 0
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... phase the array data to generate two haplotypes for each individual.
5) Predict Lp(a) as the sum of the AoU-based model predictions for the two haplotype.

The method works well (r^2=46%) with minimal population differences, indicating it captures relevant rare and structural variation.

3/3

01.03.2026 11:18 πŸ‘ 0 πŸ” 0 πŸ’¬ 0 πŸ“Œ 0
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1) In All of Us, group individuals by SNP-based haplotypes flanking the LPA locus.
2) Assign each AoU participant the Lp(a) level predicted by a sequencing-based model previously developed in the UK biobank.
3) Assign each haplotype the mean predicted Lp(a) level.
4) In the target cohort,

2/3

01.03.2026 11:18 πŸ‘ 0 πŸ” 0 πŸ’¬ 1 πŸ“Œ 0
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Genetic Prediction of Circulating Lipoprotein(a) Levels in Diverse Populations Background Circulating lipoprotein(a) [Lp(a)] levels are highly heritable and linked to atherosclerotic cardiovascular disease, yet clinical measurement rates remain low (<1%) in the United States. Th...

An interesting novel paradigm for phenotype prediction.

Lp(a) is associated with heart disease. It's highly heritable, but it's mostly influenced by repeat polymorphism, requiring sequencing data.

For array data, the authors propose the following pipeline:

1/3

www.medrxiv.org/content/10.6...

01.03.2026 11:18 πŸ‘ 3 πŸ” 0 πŸ’¬ 1 πŸ“Œ 0
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Genome-wide association analyses highlight the role of the intestinal molecular environment in human gut microbiota variation - Nature Genetics Population-based studies from Sweden with replication in Norway identify associations between host genetic variants and gut microbial composition and implicate short-chain fatty acid chemosensors as m...

Two studies performed GWAS on gut microbiome composition. One study used dataset A (Sweden) with replication in B (Norway). The other used dataset B and replicated in A. Both published in Nature Genetics.
Unbelievable.

www.nature.com/articles/s41...
www.nature.com/articles/s41...

27.02.2026 15:02 πŸ‘ 9 πŸ” 0 πŸ’¬ 2 πŸ“Œ 0
Postdoctoral Research Associate in quantitative genomics We are looking to fill a post for Postdoctoral Research Associate in quantitative genomics within the project OptiME. In this role, you will advance the state-of-the-art quantitative genetic applicati...

Two post-doc post in ARG space and loads of internal and external collaboration

Postdoctoral Research Associate in quantitative genomics
elxw.fa.em3.oraclecloud.com/hcmUI/Candid...

Postdoctoral Research Associate in quantitative genetics and breeding
elxw.fa.em3.oraclecloud.com/hcmUI/Candid...

25.02.2026 07:17 πŸ‘ 12 πŸ” 12 πŸ’¬ 1 πŸ“Œ 0
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@pratikkatte.bsky.social and I just released Lorax 🌲, a tool for interactive exploration of biobank-scale ancestral recombination graphs (ARGs).

If you’ve ever wanted to scroll across the ancestries of thousands of genomes… this is for you.

24.02.2026 15:19 πŸ‘ 38 πŸ” 26 πŸ’¬ 2 πŸ“Œ 0

New preprint! with @a-solernunez.bsky.social

Rethinking a textbook example of human adaptation "AMY1 copy number evolution in light of demographic history"

Once population structure is accounted for, the classic starch–agriculture narrative becomes much less clear

www.biorxiv.org/content/10.6...

19.02.2026 11:05 πŸ‘ 14 πŸ” 11 πŸ’¬ 0 πŸ“Œ 0
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Their Mutated Genes Were Supposed to Be Harmless β€œCarriers” of certain genetic diseases, who have just one affected gene, can have symptoms too.

Rare disease piece in @theatlantic.com, how carriers of recessive conditions can have medical problems, making them more than 'carriers'. Gift link below.

www.theatlantic.com/health/2026/...

16.02.2026 13:06 πŸ‘ 22 πŸ” 11 πŸ’¬ 2 πŸ“Œ 1
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I overall agree with the conclusions: it is important to acknowledge the limitations of shallow phenotyping, and the tradeoffs between power and specificity should be further studied.

My only criticism is perhaps too much trust in the clinical interview diagnosis - is it truly a gold standard?

15.02.2026 11:49 πŸ‘ 5 πŸ” 0 πŸ’¬ 0 πŸ“Œ 0
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The authors recommend using statistical imputation to generate estimated high-quality diagnoses from shallow but multi-dimensional biobank data.

15.02.2026 11:49 πŸ‘ 0 πŸ” 0 πŸ’¬ 1 πŸ“Œ 0
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The authors also note that if a polygenic score for a specific disorder is not only more accurate for the target disorder, but it is also more accurate for other disorders, it may just capture more of the heritable confounders.

15.02.2026 11:49 πŸ‘ 0 πŸ” 0 πŸ’¬ 1 πŸ“Œ 0
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This means that it is very difficult to interpret evidence of pleiotropy between disorders. More generally, these confounders complicate the interpretation of the GWAS results and make it difficult to learn new biology.

15.02.2026 11:49 πŸ‘ 2 πŸ” 0 πŸ’¬ 1 πŸ“Œ 0
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Specifically, shallow phenotyping studies may detect SNPs that associate with confounders.

Genetic correlations between deep/shallow phenotyping cohorts for same disorder are indeed <1.

Also, these associations are often shared across disorders, creating the impression of a shared genetic basis.

15.02.2026 11:49 πŸ‘ 0 πŸ” 0 πŸ’¬ 1 πŸ“Œ 0
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In some studies, diagnosis is based on clinical interviews (gold standard), whereas in others (e.g. 23andMe-based) it is self-reported ("Have you ever been diagnosed with clinical depression?")

The latter studies are larger, but what they actually measure is unclear and may also be heritable.

15.02.2026 11:49 πŸ‘ 0 πŸ” 0 πŸ’¬ 1 πŸ“Œ 0
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The predicament of heritable confounders - Nature Genetics This Perspective argues that diagnoses derived from self-reports, electronic health records and self-administered questionnaires introduce heritable bias that confounds the interpretation of data from...

Very interesting perspective article by @caina89.bsky.social et al on genetic studies in psychiatry.

The authors argue that studies increasingly rely on "shallow" phenotyping (self-reported), leading to biases in estimation of genetic relationships between disorders.

www.nature.com/articles/s41...

15.02.2026 11:49 πŸ‘ 32 πŸ” 8 πŸ’¬ 1 πŸ“Œ 0
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Put your skates on & register for this #ESHRE webinar ⛸️
Polygenic embryo screening (#PES): practice is moving fastβ€”ethics need to catch up.
Join this #ESHRE webinar on public views, patient experiences & clinical concerns worldwide.
πŸ—“οΈ 10 February 2026 | 17:00 CET
πŸ”— www.eshre.eu/Education/We...

05.02.2026 08:00 πŸ‘ 1 πŸ” 1 πŸ’¬ 0 πŸ“Œ 0
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🧬 Now published in Bioinformatics Advances: "pygenstrat: A Python package for EIGENSTRAT data processing" by @dilekopter.bsky.social

Full article available: https://doi.org/10.1093/bioadv/vbag022

03.02.2026 11:04 πŸ‘ 10 πŸ” 6 πŸ’¬ 1 πŸ“Œ 0
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It took scientists 11 years to compute 1-2/3=1/3

04.02.2026 20:52 πŸ‘ 10 πŸ” 1 πŸ’¬ 1 πŸ“Œ 0

Indeed.

31.01.2026 06:55 πŸ‘ 1 πŸ” 0 πŸ’¬ 0 πŸ“Œ 0
Systematic Literature Review figure of how genetic relatedness estimates are done in the wild.

Systematic Literature Review figure of how genetic relatedness estimates are done in the wild.

(1/2) The preprint of our perspective on genetic estimates of relatedness in animal populations is out! Big Congratulations to Annika!
doi.org/10.32942/X28...

A systematic review of 2,861 articles shows that, even in 2025, 75% of such studies use microsatellites. And most use only a few!

#PopGen

26.01.2026 17:35 πŸ‘ 14 πŸ” 5 πŸ’¬ 1 πŸ“Œ 0
Slack

Given several new followers here, I'm posting the link to our Slack group "genetic genealogy science".

We post and discuss manuscripts on phasing/imputation, IBD, recombination, demographic inference, ancient DNA, ancestry/admixture, etc.
All are welcome.

join.slack.com/t/geneticgen...

10.11.2024 12:21 πŸ‘ 15 πŸ” 7 πŸ’¬ 0 πŸ“Œ 0
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New Year, New Paper! #PolygenicEmbryoScreening
We examined the interaction of rare and common variation for breast cancer in the context of PES, with three key findings detailed in posts below...

14.01.2026 14:45 πŸ‘ 1 πŸ” 1 πŸ’¬ 1 πŸ“Œ 0

Tracing the evolutionary histories of ultra-rare variants using variational dating of large ancestral recombination graphs https://www.biorxiv.org/content/10.64898/2026.01.07.698223v1

12.01.2026 22:32 πŸ‘ 14 πŸ” 8 πŸ’¬ 0 πŸ“Œ 0
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Genetic influences of educational outcomes during and after the Soviet era: Revisiting evidence from Estonia The origins of individual differences in socioeconomic outcomes, including educational attainment and occupational status, reflect a combination of genetic and environmental factors whose relative con...

Previous work suggested that the role of genes in educational attainment was higher in contemporary Estonia than during the Soviet era. With a tenfold larger dataset, our new preprint finds limited evidence to support this.

www.biorxiv.org/content/10.6...

12.01.2026 09:45 πŸ‘ 8 πŸ” 3 πŸ’¬ 0 πŸ“Œ 0

Good (long) coverage here:

www.science.org/content/arti...

Sampling and sequencing of male-line descendants is underway.

09.01.2026 15:55 πŸ‘ 1 πŸ” 0 πŸ’¬ 1 πŸ“Œ 0

Global patterns of natural selection inferred using ancient DNA https://www.biorxiv.org/content/10.64898/2026.01.07.697984v1

08.01.2026 10:32 πŸ‘ 9 πŸ” 8 πŸ’¬ 0 πŸ“Œ 0
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There are 2x2 haplotype comparisons between pairs of genomes. For half-sibs, one comparison will have kinship 0.25 and the others zero. For avuncular pairs, two will be ~0.125. The maximal haplotype-haplotype kinship shows clear distinction between half-sibs (pink) and avuncular pairs (light blue).

08.01.2026 13:56 πŸ‘ 2 πŸ” 0 πŸ’¬ 0 πŸ“Œ 0