Integration of expression QTLs with fine mapping via SuSiE.
Xiangyu ZhangWei JiangHongyu ZhaoPublished in: PLoS genetics (2024)
Genome-wide association studies (GWASs) have achieved remarkable success in associating thousands of genetic variants with complex traits. However, the presence of linkage disequilibrium (LD) makes it challenging to identify the causal variants. To address this critical gap from association to causation, many fine-mapping methods have been proposed to assign well-calibrated probabilities of causality to candidate variants, taking into account the underlying LD pattern. In this manuscript, we introduce a statistical framework that incorporates expression quantitative trait locus (eQTL) information to fine-mapping, built on the sum of single-effects (SuSiE) regression model. Our new method, SuSiE2, connects two SuSiE models, one for eQTL analysis and one for genetic fine-mapping. This is achieved by first computing the posterior inclusion probabilities (PIPs) from an eQTL-based SuSiE model with the expression level of the candidate gene as the phenotype. These calculated PIPs are then utilized as prior inclusion probabilities for risk variants in another SuSiE model for the trait of interest. By prioritizing functional variants within the candidate region using eQTL information, SuSiE2 improves SuSiE by increasing the detection rate of causal SNPs and reducing the average size of credible sets. We compared the performance of SuSiE2 with other multi-trait fine-mapping methods with respect to power, coverage, and precision through simulations and applications to the GWAS results of Alzheimer's disease (AD) and body mass index (BMI). Our results demonstrate the better performance of SuSiE2, both when the in-sample linkage disequilibrium (LD) matrix and an external reference panel is used in inference.
Keyphrases
- genome wide
- copy number
- high resolution
- air pollution
- poor prognosis
- dna methylation
- body mass index
- high density
- genome wide association
- binding protein
- physical activity
- long non coding rna
- hepatitis c virus
- weight gain
- molecular dynamics
- single cell
- mild cognitive impairment
- health insurance
- health information
- adverse drug
- drug induced
- men who have sex with men
- loop mediated isothermal amplification
- affordable care act