Shared Genes Link Telomere Length to Heart Disease Risk

Telomere shortening is a hallmark of cellular aging, and shorter leukocyte telomere length (LTL) has long been associated epidemiologically with cardiovascular diseases (CVDs). However, the precise genetic mechanisms linking these traits have remained incompletely characterized. This study addresses that gap with a systematic, genome-wide cross-trait analysis using the largest available GWAS datasets in European ancestry populations.

The researchers first applied cross-trait LD score regression (LDSC) to assess genome-wide genetic correlations between LTL and six major CVDs: atrial fibrillation (AF), coronary artery disease (CAD), venous thromboembolism (VTE), heart failure (HF), peripheral artery disease (PAD), and stroke. Significant negative genetic correlations were found for LTL-PAD (rg = −0.250), LTL-CAD (rg = −0.171), LTL-HF (rg = −0.145), LTL-stroke (rg = −0.104), and LTL-VTE (rg = −0.072), while no significant correlation was observed with AF. The authors noted that genome-wide genetic correlation alone cannot distinguish scenarios where concordant and discordant genetic effects cancel each other out, motivating a deeper pleiotropic analysis.

Using multiple complementary statistical methods—including MiXeR for modeling bivariate genetic overlap, PLACO for pleiotropic locus discovery, and Bayesian colocalization—the team identified 248 pleiotropic loci shared between LTL and the CVDs. Of these, 22 demonstrated strong colocalization evidence (posterior probability >0.8). Several shared loci implicated multiple genes: the 12q24.12 region harbored ALDH2, ACAD10, TMEM116, and SH2B3 across different trait pairs, while TMED6 (16q22.1), SERPINF1 (17p13.3), and XPO7 (8p21.3) also emerged as pleiotropic candidates. Functional enrichment and pathway analyses highlighted DNA biosynthesis and telomere maintenance as the primary biological mechanisms underlying shared genetic risk.

Mendelian randomization analyses provided evidence for a causal role of LTL in CAD onset: shorter LTL was associated with increased CAD risk across multiple MR methods. Importantly, proteome-wide Mendelian randomization identified the protein product of SH2B3—a gene encoding a lymphocyte adapter protein involved in hematopoiesis and immune signaling—as a plausible mediating target, suggesting its potential as a therapeutic entry point for both telomere biology and cardiovascular risk.

These findings clarify the genetic underpinnings of the LTL–CVD relationship and offer concrete genomic targets for future mechanistic and therapeutic investigation. The convergence of telomere biology and cardiovascular pathways through shared genetic loci suggests that interventions aimed at preserving telomere integrity or modulating SH2B3 signaling could have dual benefit for aging and heart disease prevention.