Jeffrey Pullin
jeffreypullin.bsky.social
Jeffrey Pullin
@jeffreypullin.bsky.social
PhD Student, MRC Biostatistics Unit
University of Cambridge
Gates Cambridge Scholar

Bioinformatics, genetics, single-cell, statistics

Australian 🇦🇺
Pinned
Very excited to share new work from my PhD on a new software package for eQTL mapping: quasar. The quasar software package is a C++ program designed to provide a flexible and efficient eQTL mapping. www.medrxiv.org/content/10.1...
Flexible and efficient count-distribution and mixed-model methods for eQTL mapping with quasar
Identifying genetic variants that affect gene expression, expression quantitative trait loci (eQTLs), is a major focus of modern genomics. Today, various methods exist for eQTL mapping, each using dif...
www.medrxiv.org
Reposted by Jeffrey Pullin
First time on Bsky and first big announcement!

I am excited to announce that our new study explaining the missing heritability of many phenotypes using WGS data from ~347,000 UK Biobank participants has just been published in @Nature.

Our manuscript is here: www.nature.com/articles/s41....
Estimation and mapping of the missing heritability of human phenotypes - Nature
WGS data were used from 347,630 individuals with European ancestry in the UK Biobank to obtain high-precision estimates of coding and non-coding rare variant heritability for 34 co...
www.nature.com
November 12, 2025 at 5:57 PM
Reposted by Jeffrey Pullin
New pre-print: "Systematic comparison of colocalization methods using protein quantitative trait loci" led by @hwang_seongwon at www.biorxiv.org/content/10.1.... Which method does best? Find out!
Systematic comparison of colocalization methods using protein quantitative trait loci
Colocalization is frequently performed as a step to triage findings from genetic investigations linking molecular and disease data. However, the reliability and consistency of the various colocalizati...
www.biorxiv.org
November 8, 2025 at 3:40 PM
Reposted by Jeffrey Pullin
New: GWAS of serurm antibody levels. Interesting findings include genetically correlated traits with hard-to-find shared causal variants, and apparently genetically uncorrelated traits sharing causal variants that operate in inconsistent directions www.medrxiv.org/content/10.1...
Large-scale GWAS meta-analysis of serum antibody levels reveals distinct genetic architectures
Antibodies are the principal effector proteins of humoral immunity. Dysregulated antibody production is a feature of a number of heritable immune-mediated diseases, such as the antibody deficiencies a...
www.medrxiv.org
October 30, 2025 at 1:30 PM
Reposted by Jeffrey Pullin
I'm very excited to be attending my first #ASHG25 this week! Come find me at poster board 1090F to talk about flexible and efficient eQTL mapping with quasar!
October 13, 2025 at 1:23 PM
I'm very excited to be attending my first #ASHG25 this week! Come find me at poster board 1090F to talk about flexible and efficient eQTL mapping with quasar!
October 13, 2025 at 1:23 PM
Reposted by Jeffrey Pullin
Out now in Nature Comms: the largest trans-eQTL meta-analysis in a single cell type!

An Open Targets team led by Krista Freimann and @kauralasoo.bsky.social analysed 3,734 lymphoblastoid cell line samples across nine cohorts, identifying four robust loci

www.nature.com/articles/s41...
Trans-eQTL mapping prioritises USP18 as a negative regulator of interferon response at a lupus risk locus - Nature Communications | Open Targets
Out now in Nature Comms: the largest trans-eQTL meta-analysis in a single cell type! An Open Targets team led by Krista Freimann and Kaur Alasoo analysed 3,734 lymphoblastoid cell line samples across...
www.linkedin.com
October 2, 2025 at 11:59 AM
Reposted by Jeffrey Pullin
I feel incredibly privileged to share this study on Fanconi anaemia, based on a small but important cohort. This work describes the genetics and clinical outcomes of patients in Australia and New Zealand with a diagnosis of FA.

www.sciencedirect.com/science/arti...
Clinical and genetic spectrum of Fanconi anemia in Australia and New Zealand
Fanconi anemia (FA) is a rare genetic condition that predisposes to progressive bone marrow failure, a specific spectrum of malignancies, including he…
www.sciencedirect.com
September 11, 2025 at 3:50 AM
Reposted by Jeffrey Pullin
Multi-ancestry GWAS can increase power and precision, but how should we analyze them? Pooled or stratified? We answer that question in a paper out today in AJHG, led by Julie Dias and Haoyu Zhang. 1/7 www.cell.com/ajhg/fulltex...
Evaluating multi-ancestry genome-wide association methods: Statistical power, population structure, and practical implications
Multi-ancestry GWASs enhance discovery in diverse populations, but optimal methods remain debated. Using theory, simulations, and analyses from the UK Biobank and All of Us, we show that pooled analys...
www.cell.com
September 2, 2025 at 3:26 PM
Reposted by Jeffrey Pullin
New preprint alert: tinyurl.com/tenk10k-multiome. Excited to share our analysis on the impact of genetic variants on single-cell chromatin accessibility in blood, using scATAC-seq and WGS from over 1,000 donors and 3.5M nuclei as part of TenK10K phase 1 🧬
🧵👇 (1/n)
Genetic regulation of cell type-specific chromatin accessibility shapes immune function and disease risk
Understanding how genetic variation influences gene regulation at the single-cell level is crucial for elucidating the mechanisms underlying complex diseases. However, limited large-scale single-cell multi-omics data have constrained our understanding of the regulatory pathways that link variants to cell type-specific gene expression. Here we present chromatin accessibility profiles from 3.5 million peripheral blood mononuclear cells (PBMCs) across 1,042 donors, generated using single-cell ATAC-seq and multiome (RNA+ATAC) sequencing, with matched whole-genome sequencing, generated as part of the TenK10K program. We characterized 440,996 chromatin peaks across 28 immune cell types and mapped 243,273 chromatin accessibility quantitative trait loci (caQTLs), 60% of which are cell type-specific. Integration with TenK10K scRNA-seq data (5.4 million PBMCs) identified 31,688 candidate cis-regulatory elements colocalized with eQTLs; over half (52.5%) show evidence of causal effects mediated via chromatin accessibility. Integrating caQTLs with GWAS summary statistics for 16 diseases and 44 blood traits uncovered 9.8% - 30.0% more colocalized signals compared with using eQTLs alone, many of which have not been reported in prior studies. We demonstrate cell type-specific mechanisms, such as a regulatory effect on IRGM acting through altered promoter chromatin accessibility in CD8 effector memory T cells but not in naive cells. Using a graph neural network, we inferred peak-to-gene relationships from unpaired multiome data by incorporating caQTL and eQTL signals, achieving up to 80% higher accuracy compared to using paired multiome data without QTL information. This improvement further enhanced gene regulatory network inference, leading to the identification of 128 additional transcription factor (TF)-target gene pairs (a 22% increase). These findings provide an unprecedented single-cell map of chromatin accessibility and genetic variation in human circulating immune cells, establishing a powerful resource for dissecting cell type-specific regulation and advancing our understanding of genetic risk for complex diseases. ### Competing Interest Statement L.C., E.B.D., and K.K.H.F. are employed at Illumina Inc. D.G.M. is a paid advisor to Insitro and GSK, and receives research funding from Google and Microsoft, unrelated to the work described in this manuscript. G.A.F reports grants from National Health and Medical Research Council (Australia), grants from Abbott Diagnostic, Sanofi, Janssen Pharmaceuticals, and NSW Health. G.A.F reports honorarium from CSL, CPC Clinical Research, Sanofi, Boehringer-Ingelheim, Heart Foundation, and Abbott. G.A.F serves as Board Director for the Australian Cardiovascular Alliance (past President), Executive Committee Member for CPC Clinical Research, Founding Director and CMO for Prokardia and Kardiomics, and Executive Committee member for the CAD Frontiers A2D2 Consortium. In addition, G.A.F serves as CMO for the non-profit, CAD Frontiers, with industry partners including, Novartis, Amgen, Siemens Healthineers, ELUCID, Foresite Labs LLC, HeartFlow, Canon, Cleerly, Caristo, Genentech, Artyra, and Bitterroot Bio, Novo Nordisk and Allelica. In addition, G.A.F has the following patents: "Patent Biomarkers and Oxidative Stress" awarded USA May 2017 (US9638699B2) issued to Northern Sydney Local Health District, "Use of P2X7R antagonists in cardiovascular disease" PCT/AU2018/050905 licensed to Prokardia, "Methods for treatment and prevention of vascular disease" PCT/AU2015/000548 issued to The University of Sydney/Northern Sydney Local Health District, "Methods for predicting coronary artery disease" AU202290266 issued to The University of Sydney, and the patent "Novel P2X7 Receptor Antagonists" PCT/AU2022/051400 (23.11.2022), International App No: WO/2023/092175 (01.06.2023), issued to The University of Sydney. ### Funding Statement A.X. is supported by NHMRC Investigator grant 2033018. J.E.P. is supported by NHMRC Investigator grant 2034556, and a Fok Family Fellowship; D.G.M. is supported by an NHMRC investigator grant (2009982). G.A.F. and the BioHEART Study have been supported by NHMRC Investigator Grant, NSW Health Office of Health and Medical Research, and the NSW Health Statewide Biobank scheme. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The Human Research Ethics Committee of St Vincent's Hospital gave ethical approval for this work. The National Statement on Ethical Conduct in Human Research of the National Health and Medical Research Council gave ethical approval for this work. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Raw caQTL summary statistics will be available at Zenodo website prior to acceptance. [https://github.com/powellgenomicslab/tenk10k\_phase1\_multiome][1] [1]: https://github.com/powellgenomicslab/tenk10k_phase1_multiome
tinyurl.com
September 1, 2025 at 12:00 PM
Reposted by Jeffrey Pullin
After 1.5 years of work in @kauralasoo.bsky.social’s lab, we finally published my preprint! We introduce gpu-coloc, a GPU-accelerated implementation of coloc, show comparability to CLPP and aim to provide practical guidelines. Now accessible on BioRxiv: www.biorxiv.org/content/10.1...
Ultra-fast genetic colocalisation across millions of traits
Colocalisation is a powerful approach to assess if two genetic association signals are likely to share a causal variant. However, association analyses in large biobanks and molecular quantitative trai...
www.biorxiv.org
August 27, 2025 at 12:19 PM
Reposted by Jeffrey Pullin
Excited to see our (w/ @chr1sw.bsky.social) work published in @natcomputsci.nature.com! We developed a new framework, surrogate functional false discovery rate (sffdr), that integrates summary statistics of related traits to improve power in GWASs.

Paper: www.nature.com/articles/s43...
Exploiting pleiotropy to enhance variant discovery with functional false discovery rates - Nature Computational Science
This study introduces a cost-effective strategy called surrogate functional false discovery rates to increase power in genome-wide association studies by leveraging genetic correlations (or pleiotropy...
www.nature.com
August 25, 2025 at 5:04 PM
Reposted by Jeffrey Pullin
Thrilled to share the second half of my PhD work here!

We show how data on expression quantitative trait loci (eQTL) relates to the structure of gene regulatory networks (GRN). Much of the GRN / eQTL picture is unmapped, but what we do have says a lot… (1/)

doi.org/10.1101/2025...
August 22, 2025 at 7:50 PM
Really enjoying reading this paper describing the new GWAS method LDAK-KVIK - I'm particularly struck by the results describing the "difficulty of constructing accurate PGS for binary phenotypes." 1/2 www.nature.com/articles/s41...
LDAK-KVIK performs fast and powerful mixed-model association analysis of quantitative and binary phenotypes - Nature Genetics
LDAK-KVIK is a mixed-model association method for genome-wide studies that optimizes computational performance and power. LDAK-KVIK can also perform gene-based tests and produces state-of-the-art poly...
www.nature.com
August 18, 2025 at 1:44 PM
Reposted by Jeffrey Pullin
Excited to share this preprint from first author Jon Rosen, a postdoctoral fellow in the @klmohlke.bsky.social lab and my lab. We examine eQTL study sample size and how this affects signal discovery and rates of colocalization with GWAS.

www.biorxiv.org/content/10.1...
Higher eQTL power reveals signals that boost GWAS colocalization
Expression quantitative trait locus (eQTL) studies in human cohorts typically detect at least one regulatory signal per gene, and have been proposed as a way to explain mechanisms of genetic liability...
www.biorxiv.org
August 18, 2025 at 12:18 PM
Reposted by Jeffrey Pullin
Initial findings from the DecodeME genome-wide association study of myalgic encephalomyelitis/chronic fatigue syndrome now on medRXiv
www.medrxiv.org/content/10.1...
August 9, 2025 at 8:32 AM
Reposted by Jeffrey Pullin
🔔Paper alert! Extremely excited to share a preprint from our lab! Spearheaded by @axel-schmidt.bsky.social, a super talented medical & computational geneticist, we studied latent Epstein-Barr virus (EBV) infection at population-scale.

Interested in how this works & what we found? Read along! 👇
July 22, 2025 at 4:10 PM
Reposted by Jeffrey Pullin
Super excited to see this out. What started as some math in a grant in 2020, to a student deciding to take this on in 2022, to published in 2025.

These things can take time and patience is key!
July 21, 2025 at 6:54 PM
Reposted by Jeffrey Pullin
Very excited to share new work from my PhD on a new software package for eQTL mapping: quasar. The quasar software package is a C++ program designed to provide a flexible and efficient eQTL mapping. www.medrxiv.org/content/10.1...
Flexible and efficient count-distribution and mixed-model methods for eQTL mapping with quasar
Identifying genetic variants that affect gene expression, expression quantitative trait loci (eQTLs), is a major focus of modern genomics. Today, various methods exist for eQTL mapping, each using dif...
www.medrxiv.org
July 22, 2025 at 10:15 AM
Very excited to share new work from my PhD on a new software package for eQTL mapping: quasar. The quasar software package is a C++ program designed to provide a flexible and efficient eQTL mapping. www.medrxiv.org/content/10.1...
Flexible and efficient count-distribution and mixed-model methods for eQTL mapping with quasar
Identifying genetic variants that affect gene expression, expression quantitative trait loci (eQTLs), is a major focus of modern genomics. Today, various methods exist for eQTL mapping, each using dif...
www.medrxiv.org
July 22, 2025 at 10:15 AM
Reposted by Jeffrey Pullin
I'm excited to share work on a research direction my team has been advancing: connecting machine learning derived genetic variant embeddings to downstream tasks in human genetics. This work was led by the amazing Divyanshi Srivastava! www.biorxiv.org/content/10.1...
Borzoi-informed fine mapping improves causal variant prioritization in complex trait GWAS
Genome-wide association studies (GWAS) have identified thousands of trait-associated loci. Prioritizing causal variants within these loci is critical for characterizing trait biology. Statistical fine...
www.biorxiv.org
July 21, 2025 at 2:51 PM
Reposted by Jeffrey Pullin
🚨New preprint just dropped 🚨
medrxiv.org/content/10.1101/2025.06.24.25330216
The main output from my PhD is finally public and we’re SUPER excited about the findings! If you’re interested in what we learnt about IBD with a massive 700+ sample sc-eQTL dataset of the gut, read on!
July 8, 2025 at 8:52 AM
Reposted by Jeffrey Pullin
Very happy that my first PhD paper is now out in PLOS Genetics! journals.plos.org/plosgenetics.... We describe our implementation of variant-specific priors in coloc. We show that using distance to the TSS as information about which variants are causal can improve colocalisation performance, 1/n
Variant-specific priors clarify colocalisation analysis
Author summary Evaluating whether two traits, such as disease risk and gene expression, are affected by the same genetic variants is crucial for understanding the molecular mechanisms through which ge...
journals.plos.org
June 9, 2025 at 10:45 AM
Reposted by Jeffrey Pullin
Can you use variant level information in colocalisation? Yes! Will it improve accuracy on average? Yes! Will it make a substantial difference? Not using any information we could think of.

Very nice work by @jeffreypullin.bsky.social to adapt coloc to enable these questions to be addressed.
Very happy that my first PhD paper is now out in PLOS Genetics! journals.plos.org/plosgenetics.... We describe our implementation of variant-specific priors in coloc. We show that using distance to the TSS as information about which variants are causal can improve colocalisation performance, 1/n
Variant-specific priors clarify colocalisation analysis
Author summary Evaluating whether two traits, such as disease risk and gene expression, are affected by the same genetic variants is crucial for understanding the molecular mechanisms through which ge...
journals.plos.org
June 9, 2025 at 3:58 PM
Reposted by Jeffrey Pullin
Excited to share my first PhD paper in the @sbmontgom.bsky.social lab with @tamigj.bsky.social (www.biorxiv.org/content/10.1...)! Standard QTL methods treat each gene independently. But what if a single variant regulates multiple nearby genes at once - what we call “allelic proxitropy”? 🧵 ⬇️
June 8, 2025 at 5:39 PM