Diagnostic value of LMX1 B gene mutation detection in early diagnosis of children with steroid-resistant nephrotic syndrome

BAI Li-chun; QIN Yuan-han; HUANG Wei-fang; ZHOU Zhi-qiang; LEI Feng-ying; CHEN Xiu-ping

doi:10.3969/j.issn.1002-266X.2015.12.006

Abstract：Objective To discuss the diagnostic value of LMX1B gene mutation detection in the early diagnosis of children with steroid-resistant nephrotic syndrome (SRNS).Methods Normal children (control group), steroid sensitive nephrotic syn-drome (SSNS) patients (SSNS group) and SRNS patients (SRNS group) were selected, every group contained 100 cases.We used the method of PCR-SSCP for the amplification of LMX1B gene in 4, 5, 6 exons.After using agarose gel electrophoresis to i-dentify the products, single strand conformation polymorphism (SSCP) was used to analyze the PCR products.DNA sequencing was performed on the abnormal mobility or strips, and the mutation of LMX1B gene was compared between the 3 groups.Results The amplification products of exons 4, 5 and 6 complied with the purified and sequenced standards of LMX1B gene exon frag-ments.Mutations were located in the fourth exon, and no obvious mutations were found in the exons 5 and 6.Homozygous mis-sense mutation c.745G>A (R246K), SRNS group had five cases, SSNS group and control group had zero case;LMX1B gene homozygous missense mutation c.745G>A in the three groups had statistical significance (all P<0.05);homozygous missense mutation c.731-733T>C, C>G, G>A, S242R, SRNS group had 23 cases, SSNS group had 9 cases, and the control group had 2 cases, significant difference was found between the SRNS group and the control group (all P<0.05);nonsense mutation c. 733-734insT (K243*), the SRNS group had 9 cases, SSNS group had 17 cases, and none of the control group (all P<0.05);synonymous mutation c.733G>C (S242S), the SRNS group had 2 cases, the SSNS group had 11 cases, and the control group had 3 cases (all P>0.05).Conclusion LMX1B gene homozygous missense mutation c.745G>A may be the reason of the pri-mary nephrotic syndrome in children with steroid-resistant, and it has some value in the early diagnosis of SRNS.