甘露糖结合凝集素基因多态性与儿童肾病综合征频复发的关联

目的：探讨甘露糖结合凝集素（MBL）基因多态性与儿童肾病综合征（NS）频复发的关系。方法：对32例频复发肾病综合征（FRNS）、31例非频复发肾病综合征（NFRNS）患儿和32例健康儿童用序列特异性引物聚合酶链反应（PCR—SSP）法和聚合酶链反应限制性片段长度多态性（PCR—RFLP）法，分别检测MBL启动子和外显子1第54号密码子的基因多态性位点。结果：频复发组中复发前有上呼吸道感染史的患者54号密码子突变基因型（GGC／GAC型和GAC／GAC型）的发生频率（76．O％）显著高于非频复发组（42．9％）；FRNS患儿54号密码子变异型等位基因B发生频率（34．4％）显著高于健康儿童（12．5％），频复发组变异型单倍型LYB的发生频率（34．4％）显著高于正常对照组（12．5％），频复发组与变异型单倍型LYB显著相关，OR=3．66，95％可信区间（CI）为1．49～9．01。结论：MBL基因突变是儿童NS频复发的原因之一，可为儿童NS复发的预防和治疗开辟一条蹊径。

Association between mannose-binding lectin gene polymorphism and frequent relapses in childhood nephrotic syndrome

Objective: To determine whether mannose-binding lectin(MBL) variant alleles were associated with frequent relapses in childhood nephrotic syndrome(NS). Methods: MBL alleles of codon 54 and promoter region at positions-550 and-221 were genotyped by means of Polymerase Chain Reaction-Restricted Fragment Length Polymorphism(PCR-RFLP)and PCR-Sequence-Specific Primers(PCR-SSP)assay in 32 China Han Nationality children with frequently relapsing NS(FRNS) and 31 with non-frequently relapsing NS(NFRNS),as well as in 32 healthy control subjects. Results: In patients with upper respiratory infections before relapses,the mutant genotype(GGC/GAC and GAC/GAC) frequency of MBL codon 54 was higher in children with FRNS(76.0%) than in children with NFRNS(42.9%).The B allele mutation frequency of MBL codon 54 was higher in children with FRNS than in healthy control subjects(34.4% vs 12.5%,P<0.01).It was the same as the frequency of LYB haplotype and the risk of having FRNS given a mutated LYB haplotype assessed by odds ratio(OR)=3.66,95%CI:(1.49-)9.01.However,allele frequencies in promoter region were similar in children with FRNS and healthy control subjects. Conclusion: Our findings suggest that variant MBL genotypes coding for markedly diminished levels of MBL may be one of the genetic factors that determines susceptibility to FRNS and potentially amazing therapy may accrue from future interventions based on these genotypes.