R102G polymorphism of the complement component 3 gene in Malaysian subjects with neovascular age-related macular degeneration

Abstract

Background: Genetic and environmental factors are known to be risk factors in development of neovascular age-related macular degeneration (nAMD). Genetic factors such as polymorphisms in the complement component pathway genes might play a role in pathogenesis of nAMD and has been studied in various populations excluding Malaysia.

Aim of the study: To determine the association of the R102G polymorphism of the complement component (C3) gene in nAMD subjects.

Patients and methods: A total of 301 Malaysian subjects (149 case and 152 controls) were recruited and genotyped for the R102G (rs2230199) variant of the C3 gene. Genotyping was conducted using the PCRRFLP method and association analysis was conducted using appropriate statistical tests.

Results: From our findings, no significant association was observed in the allele distribution of C3 R102G between nAMD and controls (OR = 1.42, 95% CI = 0.77–2.62, P = 0.268). A further analysis that compared three genetic models (dominant, recessive and co-dominant) also recorded no significant difference (P > 0.05). These findings could be due to the low frequency of the GG variant in the case (4.7%) and control (1.3%) groups, compared to the normal variant CC, which is present in 91.3% of case and 92.8% of control alleles.

Conclusion: The present study showed no evidence of association between C3 R102G polymorphism and nAMD in Malaysian subjects.

Keywords: Age-related macular degeneration, Complement component 3, C3 gene, R102G gene polymorphism