Association of the TGF-beta1 polymorphism with primary open-angle glaucoma: a case-control study.

Abstract

Background: Primary open-angle glaucoma (POAG) is characterized by increased resistance to aqueous humor outflow. Transforming growth factor beta-1 (TGF-beta1) contributes to this resistance by promoting synthesis and remodeling of the extracellular matrix in the trabecular meshwork, thereby reducing outflow facility. This study aimed to investigate the association between the TGF-beta1 gene polymorphism at position -800 G>A (rs1800468) and POAG in patients from Khorasan Razavi Province, Iran.

Methods: In this case-control study, patients with POAG referred to Khatam-al-Anbia Hospital were enrolled as the case group, and age-matched healthy individuals served as controls. Demographic and clinical data of participants were recorded, collecting 5 mL of whole blood from each individual. DNA was extracted, genotyping the TGF-beta1 -800 G>A polymorphism using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

Results: We included 105 individuals diagnosed with POAG and 105 healthy controls, with comparable mean age and sex distribution between the two groups (both P > 0.05). In the case group, genotype frequencies were 88.6% GG (n = 93), 10.5% GA (n = 11), and 1.0% AA (n = 1), in the control group 79.0% GG (n = 83), 19.1% GA (n = 20), and 1.9% AA (n = 2). Allele frequencies were 94.0% G (n = 197) and 6.0% A (n = 13) in cases, compared to 88.6% G (n = 186) and 11.4% A (n = 24) in controls. No significant association was observed between genotype frequencies and POAG or between alleles and POAG (both P > 0.05). Analysis under various inheritance models (codominant, dominant, recessive, overdominant) showed no significant associations either (P > 0.05).

Conclusions: The TGF-beta1 -800 G>A polymorphism does not appear to play a significant role in POAG development in this population. Inheritance of the mutant A allele is not a risk factor for POAG in northeastern Iran.