Genome-wide association analyses identified novel susceptibility loci for pulmonary embolism among Han Chinese population

Abstract

Background: A large proportion of pulmonary embolism (PE) heritability remains unexplained, particularly among the East Asian (EAS) population. Our study aims to expand the genetic architecture of PE and reveal more genetic determinants in Han Chinese.

Methods: We conducted the first genome-wide association study (GWAS) of PE in Han Chinese, then performed the GWAS meta-analysis based on the discovery and replication stages. To validate the effect of the risk allele, qPCR and Western blotting experiments were used to investigate possible changes in gene expression. Mendelian randomization (MR) analysis was employed to implicate pathogenic mechanisms, and a polygenic risk score (PRS) for PE risk prediction was generated.

Results: After meta-analysis of the discovery dataset (622 cases, 8853 controls) and replication dataset (646 cases, 8810 controls), GWAS identified 3 independent loci associated with PE, including the reported loci FGG rs2066865 (p-value = 3.81 × 10^-14), ABO rs582094 (p-value = 1.16 × 10^-10) and newly reported locus FABP2 rs1799883 (p-value = 7.59 × 10^-17). Previously reported 10 variants were successfully replicated in our cohort. Functional experiments confirmed that FABP2-A163G(rs1799883) promoted the transcription and protein expression of FABP2. Meanwhile, MR analysis revealed that high LDL-C and TC levels were associated with an increased risk of PE. Individuals with the top 10% of PRS had over a fivefold increased risk for PE compared to the general population.

Conclusions: We identified FABP2, related to the transport of long-chain fatty acids, contributing to the risk of PE and provided more evidence for the essential role of metabolic pathways in PE development.

Keywords: GWAS; Han Chinese; Pulmonary embolism.

Fig. 1

Study workflow

Fig. 2

Manhattan plot and QQ plot of GWAS meta-analysis. A Manhattan plot of the results from meta-analysis. The y-axis represents –log₁₀(p-values) for the association of variants with VTE using a logistic regression model. The horizontal line represents the threshold for genome-wide significance. Representative loci with genome-wide significance are labeled. B QQ plot of the results from meta-analysis. λ_GC denotes the genomic inflation factor. The x- and y-axes represent expected and observed − log₁₀(p-values), respectively

Fig. 3

Forest plots for 3 loci associated with pulmonary embolism. Study cohorts, sample sizes (case and control), and estimated odds ratios (OR) for A rs1799883, B rs2066865, and C rs582094.The vertical line corresponds to the null hypothesis (OR = 1). The horizontal lines and square brackets indicate 95% confidence intervals (95% CI). Areas of the boxes are proportional to the weight of the study. Diamonds represent combined estimates for fixed‐effect analysis. The heterogeneity index, I² (0–1) was also measured which quantifies the proportion of the total variation due to heterogeneity. All statistical tests were two-sided and no adjustments were made for multiple comparisons

Fig. 4

FABP2 mutant enhanced itself expression compared to WT by qPCR and Western-blot experiments. A qPCR results showed effects on transcription level of FABP2 by transfected Vector, WT and MT-A163G plasmids. B, C Western Blots results showed effects on protein expression level of FABP2 by transfected vector, WT, MT-A163G plasmids. WT, wildtype; MT-A163G, mutation type with FABP2; *P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001; ns, not significant

Fig. 5

Ancestry-specific polygenic risk score (PRS) distribution and odds ratio of PRS quantiles. A Density distribution of the standardized PRS in cases and controls. AUC, area under the receiver operating characteristic curve. B Odds ratio of samples divided into different quantile bins using PRS with the 30–70% quantile chosen as the reference. Error bars indicate the 95% confidence interval