Abstract
Purpose: :
Macular pigment, composed of mainly lutein and zeaxanthin, is hypothesized to protect against age-related macular degeneration (AMD). The pi isoform of glutathione S-transferase (GSTP1) is a specific zeaxanthin-binding protein in the human macula. This study aimed to investigate the association between single nucleotide polymorphisms (SNPs) in GSTP1 gene and the risk of exudative AMD in a Chinese case-control cohort.
Methods: :
One hundred thirty-one Chinese patients with exudative AMD and 138 control individuals were recruited. Genomic DNA was extracted from venous blood leukocytes. Two common non-synonymous SNPs in GSTP1 (rs1695 and rs4986948) were genotyped by PCR followed by allele-specific restriction enzyme digestion and direct sequencing.
Results: :
Significant association with exudative AMD was detected for SNP rs1695 (p=0.019). The risk G allele frequencies were 21.8% in AMD cases and 12.7% in controls (p=0.007). Compared with the wild-type AA genotype, odds ratio (OR) for the risk of AMD was 1.91 (95% CI, 1.09-3.35) for the heterozygous AG genotype and 2.52 (95% CI, 0.6-10.61) for the homozygous GG genotype. In contrast, rs4986948 was not associated with exudative AMD (p=1.00). The risk G allele frequencies of rs4986948 were 0.4% in AMD cases and 0.4% in controls (p=1.00).
Conclusions: :
Our data suggest that the GSTP1 variant rs1695 moderately increases the risk of exudative AMD. The variant rs4986948 was rare and not associated with exudative AMD in this Chinese cohort.
Keywords: age-related macular degeneration • genetics • candidate gene analysis