Highlight
- Clonal hematopoiesis of indeterminate potential (CHIP) independently elevates the risk of incident age-related macular degeneration (AMD) by 14%.
- Mutations in DNMT3A, spliceosome, and DNA damage repair genes notably contribute to heightened AMD risk.
- A high polygenic risk score (PRS) for AMD synergistically interacts with CHIP, leading to a more than threefold increased risk of AMD.
- The interplay between CHIP and genetic predisposition is particularly pronounced in older adults, suggesting age-related amplification of these risk factors.
Study Background
Age-related macular degeneration (AMD) is a leading cause of vision loss in older adults worldwide, characterized by progressive degeneration of the macula, a critical region of the retina responsible for central vision. The burden of AMD is increasing with global aging populations, highlighting an urgent need to understand its pathogenesis and identify precise risk stratification strategies. While inherited genetic factors have long been recognized as strong contributors to AMD susceptibility, novel biologically plausible risk factors are emerging. Clonal hematopoiesis of indeterminate potential (CHIP), defined by acquired somatic mutations in hematopoietic stem cells leading to clonal blood cell expansion, is increasingly implicated in age-related diseases mediated by inflammation and altered immune responses. CHIP’s role in cardiovascular and hematological disorders has been established, but its prospective relationship with AMD incidence remains unexplored. This study addresses the unmet need for longitudinal data evaluating the interplay between CHIP and genetic predisposition on the development of AMD, offering insights that may refine risk prediction and disease mechanistic understanding.
Study Design
This prospective cohort study utilized data from the UK Biobank, encompassing 395,505 participants with available blood-derived whole exome sequencing. CHIP status was ascertained based on detection of somatic mutations in leukemia-associated driver genes with a variant allele fraction of at least 2%. The study defined AMD outcomes incident over a median follow-up of 15.5 years through linked clinical records. An established polygenic risk score (PRS) incorporating validated AMD susceptibility variants was also calculated for each participant. Cox proportional hazards models were employed to evaluate the independent association of CHIP and PRS with incident AMD and to explore potential interactions. Subgroup analyses assessed gene-specific mutation effects and the influence of age on observed associations.
Key Findings
During follow-up, 7,178 incident AMD cases were documented. Overall, CHIP presence correlated with a 14% increased hazard of developing AMD (HR 1.14, 95% CI 1.03–1.26, P=0.009). Among CHIP mutations, DNMT3A mutations demonstrated a significant association (HR 1.20, 95% CI 1.06–1.36, P=0.005). Spliceosome gene mutations and DNA damage repair gene mutations were also implicated, conferring hazards of 1.72 (95% CI 1.02–2.97, P=0.042) and 1.68 (95% CI 1.06–2.67, P=0.028), respectively.
Parallel evaluation revealed that a high AMD polygenic risk score was a strong predictor of incident AMD independently. Strikingly, participants harboring both any CHIP mutation and a high PRS faced a 3.26-fold increased risk of AMD (95% CI 2.75–3.86, P<0.001) relative to those lacking both risk factors. Evidence for additive interaction was supported by a relative excess risk due to interaction (RERI) of 0.60 (95% CI 0.07–1.20), indicating synergism beyond an additive effect. The joint effect was accentuated in DNMT3A mutation carriers combined with high PRS, with a hazard ratio reaching 3.69 (95% CI 2.58–3.96, P<0.001) and an RERI of 0.34 (95% CI 0.04–1.12). Importantly, these synergistic associations were more pronounced in older adult subsets, highlighting the age-dependence of CHIP and genetic susceptibility interplay.
Expert Commentary
This large-scale prospective analysis provides compelling epidemiological evidence that somatic clonal hematopoiesis elevates AMD risk independent of inherited genetic predisposition. The biological plausibility links to CHIP-driven systemic inflammation, immune dysregulation, and altered myeloid cell function, which may exacerbate retinal degeneration mechanisms. The identification of specific driver genes such as DNMT3A, which regulates DNA methylation and hematopoietic differentiation, and spliceosome components involved in RNA processing, offers mechanistic clues warranting further functional study.
Moreover, the demonstrated additive interaction between CHIP and AMD PRS underscores a complex, multifactorial disease architecture where somatic mutations and germline variants synergize to modulate disease susceptibility. This interplay aligns with emerging paradigms positing that age-related accumulation of somatic mutations contributes to chronic inflammatory states, potentiating genetically predisposed pathways leading to tissue damage.
The study’s strengths include its large, well-phenotyped population with prolonged follow-up and robust mutation detection methodology. However, limitations include potential residual confounding, reliance on variant allele fraction thresholds that may omit smaller clones, and generalizability issues as UK Biobank participants are predominantly of European descent. Also, AMD diagnosis was based on clinical records rather than standardized ophthalmic examinations, which might introduce some misclassification.
Clinically, these findings support the potential utility of integrating somatic mutation screening with polygenic risk assessment to improve AMD risk stratification, particularly for elderly patients. Future prospective interventional studies may explore if targeting CHIP-associated inflammatory pathways can modify AMD progression.
Conclusion
Clonal hematopoiesis of indeterminate potential is an independent and synergistic risk factor for incident age-related macular degeneration, especially in conjunction with high genetic susceptibility. This novel insight expands our understanding of AMD pathogenesis by incorporating somatic mutational processes as well as inherited genetic predisposition. The amplified risk observed in older adults highlights an age-related biological convergence potentially driven by inflammation and immune dysfunction. Ultimately, these findings advocate for comprehensive AMD risk prediction models encompassing somatic and germline genomic dimensions, informing personalized prevention strategies and novel therapeutic targets in the aging population.
Funding and Trials Information
The study was conducted using the UK Biobank resource with funding support for genomic analyses from institutional grants. Details regarding specific funding sources and clinical trial registrations were not provided in the original publication.
References
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2. Fritsche LG et al. A large genome-wide association study of age-related macular degeneration highlights contributions of rare and common variants. Nat Genet. 2016;48(2):134-143.
3. Young AL et al. Clonal haematopoiesis harbouring AML-associated mutations is ubiquitous in healthy adults. Nat Commun. 2016;7:12484.
4. Li FR et al. Clonal Hematopoiesis of Indeterminate Potential and Genetic Susceptibility in Incident Age-Related Macular Degeneration: A Cohort Study. Am J Ophthalmol. 2026 Jul 8; PMID: 42419444.
