Association of the -449GC and -1151AC polymorphisms in the DDAH2 gene with asymmetric dimethylarginine and erythropoietin resistance in Chinese patients on maintenance hemodialysis.

We investigated the association of the -449G/C and -1151A/C polymorphisms in the DDAH2 gene with plasma asymmetric dimethylarginine (ADMA) concentration and erythropoietin resistance in 131 Chinese patients on maintenance hemodialysis (MHD). The -449G allele was in complete linkage disequilibrium with the -1151A allele and so were their corresponding C alleles. The -449GG/-1151AA genotype had the highest plasma ADMA concentration, erythropoietin resistance index (EPI) and serum malondialdehyde level, compared to either the -449GC/-1151AC or -449CC/-1151CC variation. The genetic effect on the ADMA and EPI was separately confirmed by multivariate regression analysis. Our findings suggested that complex genetic variations in the DDAH2 gene may influence the ADMA concentration and erythropoietin resistance in MHD patients, in which altered oxidative stress was likely involved.