【摘要】 目的　检测中国汉族家族性高胆固醇血症 (FH)家系低密度脂蛋白受体 (LDLR)基因突变类型 ,研究基因型与表型间的关系 ,探讨FH发病的分子病理机制。方法　先证者及家系成员进行血脂测定、心电图、心脏及大血管彩色多普勒超声检查后采用聚合酶链反应 ( polymerasechainreaction ,PCR) 变性高效液相色谱 (DHPLC)法结合扩增产物直接序列分析检测LDLR基因启动子和全部 18个外显子片段 ,结果与GenBank公布的该基因正常序列比对找出突变并检索FH突变数据库(www .ucl.ac .uk/fh)。此外 ,采用PCR 限制性内切酶技术 ,检测载脂蛋白B10 0 (ApoB10 0 )基因Q35 0 0R突变 ,以排除家族性ApoB10 0 缺陷症 (FDB)。结果　DHPLC分析发现该患儿及其父母LDLR基因第 3外显子存在一异常波峰 ,DNA测序证实该患儿第 3内含子 5′剪接位点存在G→A纯合剪接突变 ,其父母相同位点表现为野生型和突变型杂合现象 ;同时未检测出患儿及其父母ApoB10 0Q35 0 0R突变。结论　国内首次发现LDLR基因第 3内含子G→A纯合剪接突变 ;该突变可能是FH发病的分子基础并导致其严重的临床表型 ;PCR DHPLC法可用于FH可疑人群的确诊更多还原

【Abstract】 Objective To analysis the mutation of low density lipoprotein receptor(LDLR) gene in a Chinese family with familial hypercholesterolemia(FH) and make a discussion on the relationship between genotype and phenotype. Methods The promoter and all eighteen exons of LDLR gene were investigated by Touch down PCR, DHPLC and DNA sequence analysis. The results were compared with the normal sequences in GenBank and FH database(www.ucl.uk/fh) to find the mutation. In addition, we screened the apolipoprotein B 100 (ApoB 100 ) gene for the known mutations (R3500Q) that cause familial defective ApoB 100 (FDB) by PCR RFLP. Results A novel homozygous G→A mutation in the splice donor of LDLR intron 3 was detected. No mutations R3500Q of ApoB 100 were observed. Conclusion The homozygous G→A splice mutation of LDLR gene was firstly determined in the our country. The change of the splice donor in LDLR intron 3 may cause skipping of exon 3, which is probably responsible for FH. Perhaps it is a particular pathogenesis for Chinese people. PCR DHPLC used for could be made by detecting the mutation.更多还原