G protein β3 subunit 825T genotype is not associated with differing outcome in pediatric renal transplant recipients

Recent studies have identified a novel polymorphism (C825T) of the gene encoding the β3 subunit of heterotrimeric G proteins (GNB3), associated with enhanced activation of G proteins, which appears to be more common in hypertensive patients. The donor GNB3 825TT genotype was associated with reduced kidney allograft survival in adults. We examined (in 100 Caucasian pediatric renal transplant recipients) whether the GNB3 (C825T) polymorphism was associated with disease progression and outcome after renal transplantation. The slope of 1/creatinine was determined by linear regression analysis of a median of 12 points before and after renal transplantation, and the population was divided into two groups of equal size, before and after transplantation, according to the slope. The observed frequencies were 57 for the CC, 33 for the CT, and 10 for the TT haplotype. For comparison, 738 consecutive newborn babies with the same ethnic background were typed in the same hospital. Allele frequencies were statistically not significantly different (chi-square test, p = 0.1327). When dividing the pediatric renal transplant recipients into two groups with regard to the slope of 1/creatinine, both before and after renal transplantation, the observed proportions were CC 26, CT 17, and TT 7 in the group with the poorer slope and CC 31, CT 16, and TT 3 in the group with the better slope before renal transplantation (not significant [NS], chi-square test, p = 0.1777). The observed proportions after renal transplantation were CC 26, CT 16, and TT 8 in the group with the poorer slope and CC 31, CT 15, and TT 4 in the group with the better slope, respectively (NS, chi-square test, p = 0.167). Allograft survival was not associated with the T allele. In conclusion, in a sizeable number of pediatric renal transplant recipients the GNB3 C825T polymorphism was found not to be a genetic risk factor for end-stage kidney disease. In addition, kidney graft function and survival was also found not to be associated with a recipient GNB3 C825T polymorphism.