Association of the Y402H polymorphism in complement factor H gene and neovascular age-related macular degeneration in Chinese patients

Abstract

Purpose: Age-related macular degeneration (AMD), with its complex traits and multiple risk factors, is the leading cause of blindness in the elderly. A strong association between a coding variant, Y402H, in the complement factor H gene (CFH) and AMD has been recently identified in white patients. This study was conducted to investigate the association between the Y402H polymorphism in CFH and neovascular AMD in Chinese patients.

Methods: One hundred sixty-three Chinese patients with neovascular AMD and 232 age-matched healthy controls were enrolled in the study. Genomic DNA from white blood cells was extracted. The Y402H polymorphism in CFH, with the substitution of T to C at nucleotide position 1277 in exon 9, was determined by polymerase chain reaction-restriction fragment length polymorphism analysis. The association between the genetic polymorphism and the disease was examined by chi(2) test and logistic regression.

Results: The frequency of the risk allele, 1277C, was 11.3% in AMD patients compared with 2.8% in controls (P < 0.00001). Genotype frequency differed significantly between the two groups (1277TT 81.0%, 1277TC 15.3%, and 1277CC 3.7% in the AMD group; 1277TT 94.4%, 1277TC 5.6%, and 1277CC 0% in the control group; P < 0.0001). The 1277C allele significantly increased the risk for neovascular AMD and had an odds ratio of 4.4 (95% confidence interval [95% CI], 2.3-8.5; P < 0.00001).

Conclusions: The allele frequency of Y402H polymorphism in CFH has an ethnic variation, with much lower 1277C frequency in Chinese than in white patients. Despite this, the polymorphism is significantly associated with neovascular AMD in the Chinese population.