Association between endothelin receptor type A gene polymorphisms EDNRA (C+70G, C+1222T) and the endothelin‐1 plasma concentration in patients with normal tension glaucoma

Purpose The purpose of his study was to determine the prevalence of endothelin receptor type A gene polymorphisms EDNRA (C+70G, C+1222T) and its correlation to the plasma concentration of endothelin‐1 (ET‐1) in patients with normal tension glaucoma (NTG). Methods The study enrolled 36 NTG patients including 23 women and 13 men. In order to analyze the frequency of polymorphic variants of endothelin receptor type A genes EDNRA (C+70G, C+1222T), DNA was isolated from peripheral blood and SNP (Single Nucleotide Polymorphism) genotyping was performed using RT‐PCR method (Real‐Time Polymerase Chain Reaction). The plasma ET‐1 concentration was detected using an enzyme immunoassay. Results Analysis of the prevalence of endothelin receptor type A gene polymorphisms EDNRA C+70G was: GG‐30,5%, CC‐14,0%, CG‐ 55,5%. The frequency of the genotype GG tended to be higher in women than in men (p=0,07). The prevalence of endothelin receptor type A gene polymorphisms EDNRA C+1222T was as follows: TT‐8,3%, CC‐33,3%, CT‐58,6%. The frequency of the genotype CC tended to be higher in women than in men (p=0,19). The mean ET‐1 level was 1,49±0,71 fmol/ml. The GG genotype of EDNRA C+70G was associated with higher plasma ET‐1 concentration in women group (p=0,02), moreover the CT genotype of EDNRA C+1222T was related to higher plasma ET‐1 concentration in women (p=0,006) and in men (p=0,02). Conclusion In NTG patients the endothelin receptor type A gene polymorphisms EDNRA (C+70G, C+1222T) may have correlation with higher plasma ET‐1 concentration.