A Molecular Insight of the Role of PIN-1 Promoter Polymorphism (- 667C > T; rs2233679) in Chronic Kidney Disease Patients with Secondary Hyperparathyroidism.

Abstract

Murine studies stipulate Peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (PIN-1) as a key mediator of PTH mRNA stability and is acknowledged by genome-wide-association-studies as secondary hyperparathyroidism defining trait in chronic kidney disease. Therefore, we hypothesize that molecular variants of the PIN-1 gene might affect the incidence and predisposition to secondary hyperparathyroidism in chronic renal insufficiency. A total of 281 adult participants, including 124 chronic kidney disease patients with secondary hyperparathyroidism and 157 healthy controls, were genotyped using polymerase chain reaction-restriction fragment length polymorphism method to unravel the effects of genetic risk loci (PIN-1 gene; - 667C > T; rs2233679) on the susceptibility to secondary hyperparathyroidism in chronic kidney disease. Suitable descriptive statistics was used for different variables. The genotype (x2: 8.03, 2 d. f. p = 0.0181) and allele distribution (x2: 7.27, 2 d. f. p: 0.007) of the - 667C > T variant differed significantly in cases and controls, with no deviation from Hardy-Weinberg equilibrium in either affected or control group. The observed frequencies of T allele of PIN-1 -667 C > T SNP was significantly high in CKD-SHPT group compared to control group (52.41% vs. 41.71%; p: 0.0118). TT variant of PIN-1 - 667C > T SNP was associated with increased risk for occurrence of CKD-SHPT in univariate analysis (OR: 4.6, p: 0.0032, 95% CI: 1.66-12.76). Further in multivariate analysis, both TT (OR: 3.84, p: 0.002, 95% CI: 0.79-9.26) and CT + TT (OR: 2.51, p: 0.031, 95% CI: 0.64-8.68) variants were independently associated with increased risk for CKD-SHPT, emphasizing the deleterious effect of minor T allele. Serum PTH, phosphorus levels were significantly high in CT and TT genotypes compared to CC genotype of PIN-1 -667C > T SNP (p = 0.001). PIN-1 promoter functional SNP (- 667C > T; rs2233679) appeared to be an important genetic determinant in etiopathogenesis of CKD-SHPT and genetic variants of this SNP influences the risk stratification and might serve as a predictive marker. Thus, rs2233679 can be useful for outcome predictions during diagnostic processes.