ABCB1 gene polymorphism in nephrotic syndrome

Nephrotic syndrome is the most prevalent glomerular disease in childhood. This study illustrates distribution of the most common three multidrug resistance gene 1 MDR1 (ABCB1) exonic polymorphisms G3435C, G2677 T/A, and C1236T in children with NS to assess their ability to be used as markers for response of NS to steroids. This study aimed to find association between ABCB1 gene polymorphisms and haplotypes and NS and if they can affect their response to steroids. ABCB1 gene polymorphisms in our cases were analyzed using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). Our cases were divided into three groups: one group included 50 steroid sensitive nephrotic syndrome (SSNS) patients, another group included 100 steroid resistant nephrotic syndrome (SRNS) patients, and the third group for 100 age and sex-matched children (control group). ABCB1 C3435T TT, CT + TT genotypes, T allele; ABCB1 G2677A/T GT + GA, TT + AA, GT + GA + TT + AA genotypes, T + A allele frequencies were significantly higher in patients with NS compared to control group. Also, SRNS group showed significantly more frequencies of ABCB1 G2677A/T GT + GA, TT + AA, GT + GA + TT + AA genotypes, T + A allele than SSNS group. TTT + TAT, TTC + TAC haplotype of ABCB1 was also higher in NS patients compared to healthy control subjects. We found that the associations of ABCB1 G2677T/A and C3435T polymorphisms were observed in patients with NS. The ABCB1 G2677 T/A polymorphism was significantly increased in SRNS when compared to SSNS.