nirav-shah.bsky.social
@nirav-shah.bsky.social
Takeaway: Tractor Nextflow makes ancestry-aware GWAS harmonized, reproducible, and scalable, helping researchers include admixed individuals and uncover genetic signals missed by traditional methods.
September 8, 2025 at 12:23 PM
We also provide pre-curated LAI reference panels for 2-way AFR–EUR and 3-way AFR–EUR–AMR from TGP-HGDP reference dataset.

Check: github.com/Atkinson-Lab...
TractorWorkflow/resources at main · Atkinson-Lab/TractorWorkflow
Nextflow pipeline for Tractor GWAS with customizable phasing, local ancestry inference (RFMix2, GNomix, FLARE), and regression modules. - Atkinson-Lab/TractorWorkflow
github.com
September 8, 2025 at 12:23 PM
Tractor Nextflow Workflow solves this:
* Automates all steps from QC’d VCF to Tractor GWAS
* Modular & scalable
* Supports multiple tools: SHAPEIT5, RFMix2, FLARE, GNomix
* Can run anywhere: local, HPC, cloud
September 8, 2025 at 12:23 PM
However, running Tractor is a multi-step process:
* Module 1: Accurate phasing
* Module 2: Local ancestry inference
* Module 3: Tractor GWAS

This means multiple tools, scripts and reference panels to decide from.
September 8, 2025 at 12:23 PM
Solution: Tractor GWAS
* Models local ancestry for robust association testing
* Produces ancestry-specific summary statistics
* Detects ancestry-enriched hits missed by standard GWAS
September 8, 2025 at 12:23 PM
Documentation: atkinson-lab.github.io/TractorWorkf...

Problem: Admixed individuals are often excluded due to population stratification, even though they make up a substantial portion of modern biobanks. This could lead to missed genetic discoveries.
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Nextflow to simplify running Tractor
atkinson-lab.github.io
September 8, 2025 at 12:23 PM