Impact of age-related maculopathy susceptibility 2, high-temperature requirement A serine peptidase 1, and complement factor H genetic variants on clinical phenotypes of age-related macular degeneration.

PURPOSE: Age-related macular degeneration (AMD) is a leading cause of irreversible vision loss in the elderly. This study investigated the association of single-nucleotide polymorphisms (SNPs) in ARMS2, HTRA1, and CFH with AMD and its clinical phenotypes and systemic cytokine profiles in a North Indian population.

METHOD: A total of 113 AMD patients and 99 controls were genotyped using TaqMan assays. All patients underwent detailed ophthalmic evaluations, including optical coherence tomography (OCT), fundus photography, and angiography-based imaging. Serum cytokine levels were quantified using bead-based multiplex immunoassay and analyzed via flow cytometry. Statistical analyses were performed using SPSS v23.0, employing t-tests, ANOVA, and Mann-Whitney U tests.

RESULTS

Significant associations were observed between AMD and control for risk alleles in ARMS2 (36.3% vs 10.1%, P = 0.001), HTRA1 (37.2% vs 33.3%, P = 0.003), and CFH (27.4% vs 13.1%, P = 0.001). Genotype-phenotype correlations revealed that heterozygous and homozygous risk genotypes were significantly associated with hallmark AMD features such as pigment epithelial detachment (PED), choroidal neovascular membrane (CNVM), large drusen, and retinal pigment epithelium (RPE) atrophy. Cytokine profiling showed significantly reduced levels of erythropoietin (EPO) in AMD patients and granulocyte colony-stimulating factor (G-CSF) in controls (P = 0.044 and P = 0.023).

CONCLUSION

This study establishes novel genotype-phenotype correlations for ARMS2, HTRA1, and CFH SNPs in a North Indian cohort, linking heterozygous/homozygous risk alleles to distinct AMD clinical features. Reduced EPO and G-CSF levels suggest impaired neuroprotective/anti-inflammatory mechanisms, revealing dual pathways in AMD pathogenesis. By integrating these findings with global data, future efforts can deepen our understanding of AMD's complex etiology and improve patient outcomes worldwide.