Abstract: 【Abstract】Objective To analyze the correlation between the TaqI polymorphism in vitamin D receptor gene and the prognosis of chronic kidney disease (CKD) patients on dialysis, in order to evaluate the gene polymorphism relating to the prognosis of the patients. Methods This was a casEcontrol study. Seventy-five CKD patients on dialysis admitted to Chengdu First People's Hospital from April 2015 to April 2016 were recruited as the observation group, and 70 healthy patients undergoing physical examination in Chengdu First People's Hospital were selected as the control group. PCR products were digested with the restriction enzyme and then separated in agarose gels to identify the TaqI polymorphism. Genotype of the TaqI polymorphism in
vitamin D receptor gene, results of follow-up study and survival rate after one year were compared between the two groups. Clinical characteristics, survival rate and median survival time were also compared in patients with different genotypes of the polymorphism. Results In observation group, the genotype frequency of TaqI polymorphism in vitamin D receptor gene was TT genotype 34 cases, Tt genotype 23 cases, and tt genotype 18 cases, demonstrating that the frequency of tt genotype was lower in observation group than in control group (χ2=9.504, P=0.002) and the frequencies of TT genotype and Tt genotype were similar between the two groups (χ2=2.362 and 2.838 respectively, P=0.124 and 0.092 respectively). The total mutation rate was 76.00% in observation group, higher than that in control group (51.43%; χ2=29.504,P=0.002). There were no significant differences in sex, age, primary disease, low density lipoprotein,high density lipoprotein, triglyceride, urea nitrogen, serum creatinince, calcium, pbosphorus and 1,25 (OH)2D3 among the patients with TT genotype, Tt genotype and tt genotype (χ2= 0.308, P=0.857; F=0.272, P=0.762; χ2=3.682, P=0.720; F=0.027,P=0.973; F=0.136, P=0.824; F=0.053, P=0.948; F= 0.157, P=0.855; F=0.020, P=0.980; F=0.020, P=0.971; F=0.177, P=0.838; F=0.297, P=0.744). The results of follow-up study for one year showed that 56 of the 75 patients(74.67%) survived. The onEyear survival rate was 74.6% (56/75 survived). The onEyear survival rate and median survival time were statistically higher in patients with tt genotype than in those with Tt genotype and TT genotype(χ2=6.871, P=0.032; F=78.697, P＜0.001). Conclusion The genotype frequency of TaqI polymorphism in vitamin D receptor gene was different between CKD patients on dialysis and healthy people, and was closely related to the survival rate and survival time of the patients. The survival time was shorter in patients with mutation, which can be used for the prognostic prediction.

Key words: Chronic kidney disease dialysis, TaqI polymorphism in vitamin D receptor gene, Prognosis