摘要目的 分析1个脂蛋白肾小球病家系的载脂蛋白E(apolipoprotein E,apoE)基因突变.方法 用盐析法提取该家系4名成员和2名正常人的外周血基因组DNA,PCR扩增apoE基因第4外显子、第3外显子以及多态性片段,扩增产物纯化后分别构建到pTA2载体中,克隆载体转化至大肠杆菌DH5α感受态中,经蓝白斑和抗菌素筛选后集菌,提取重组子质粒,EcoRⅠ酶切鉴定是否转化成功,鉴定正确的菌液行双向测序.PCR-限制性片段长度多态性检测apoE基因多态性.结果 家系中先证者及其母亲和姐姐apoE基因第4外显子第484～492位9个碱基(CAAGCTGCG)缺失,为杂合缺失,其导致apoE氨基酸序列第143～145位KLR的3个氨基酸缺失.第3外显子测序未发现异常.apoE基因多态性分析结果与测序结果一致.结论 该家系的脂蛋白肾小球病因可能为apoE基因第484～492位9个碱基(CAAGCTGCG)缺失.

abstractsObjective To identify potential mutation of apolipoprotein E(apoE) gene in a male patient affected with lipoprotein glomerulopathy (LPG),his mother and his sister.Methods The patient and his mother both had histologically confirmed LPG.His sister and his father were asymptomatic.Genomic DNA was extracted from peripheral blood samples.PCR products of the coding region of exons 3 and 4 of the apoE gene were cloned into a pTA2 vector and sequenced.Genetic variations of the apoE gene were detected using PCR and restriction fragment length polymorphism (RFLP).Results An apoE gene mutation was identified in the patient's family.Sequence analysis confirmed a 9-bp deletion in the exon 4 of apoE gene from nt 484 to 492.The 9-bp deletion resulted in loss of 3 amino acids at positions 143 145.The sister of the propositus carried the same mutation,though she had neither proteinuria nor elevated plasma apoE.Sequence analysis of exon 3 showed no abnormality.No abnormalities were found in the father's apoE gene sequence.Analysis of genetic variations of the apoE gene by PCR and RFLP confirmed a 57 bp fragment consistent with the 9-bp deletion in exon 4.The father had a normal ε3ε3 genotype.Conclnsion The 9 bp deletion of apoE may be associated with the pathogenesis of LPG.