MDR1 rs1128503, rs1045642, and rs2032582 polymorphisms are not associated with INS susceptibility; however, there is evidence of an association between rs1128503 and increased risk of steroid resistance in children with INS, which indicates MDR1 may play a role in steroid resistance found in children with INS.
The purpose of the study was to investigate the distribution of insertion/deletion (I/D) polymorphisms of the angiotensin-converting enzyme (ACE) gene and three exonic polymorphisms of the multidrug resistance 1 (MDR1) gene (C3435T, C1236T, and G2677T) in children diagnosed with idiopathic nephrotic syndrome (INS).
Our results indicate that among our pediatric patients with INS the C1236T polymorphism in the ABCB1 gene was associated with steroid resistance, while the A6986G polymorphism in the CYP3A5 gene showed a trend of association, but did not reach statistical significance, requiring further analysis.