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.
Home
Nextflow to simplify running Tractor
atkinson-lab.github.io
September 8, 2025 at 12:23 PM
🚨 New preprint! Traditional GWAS often exclude admixed individuals, missing ancestry-enriched genetic signals. We built Tractor Nextflow Workflow - a modular, scalable pipeline that automates phasing, LAI, and Tractor GWAS, alongside comprehensive documentation.
Preprint: doi.org/10.1101/2025...
Tractor Workflow Pipeline: A Scalable Nextflow Framework for Local Ancestry-Aware Genome-Wide Association Studies
The routine exclusion of admixed individuals from traditional Genome-Wide Association Studies (GWAS) due to concerns about spurious associations has hindered genetic analyses involving multiple ancest...
www.biorxiv.org
September 8, 2025 at 12:23 PM