CAJ | 학술논문

目的检测家族性高胆固醇血症(familial hypercholestero-lemia,FH)患者低密度脂蛋白受体(low density lipoprotein receptor,LDLR)的基因突变.方法提取家系中,临床通过典型特征和血脂检测诊断为家族性高胆固醇血症患者的基因组DNA,首先检测载脂蛋白B100(apoB100)基因R3500Q突变,以排除家族性apoB100缺陷症(Familial defective apoB100,FDB).然后用降落聚合酶链反应(TOUCH-DOWN PCR)扩增该基因的启动子和全部18个外显子,再用单链构象多态性(SSCP)方法分析PCR产物,并对电泳结果异常者进行DNA测序分析.用ANTHEPROT 5.0软件对突变LDLR进行二级结构分析,然后对突变LDLR进行SWISS MODEL在线三级结构预测.结果通过SSCP和DNA测序发现该家系患者13号外显子存在A606T的纯合突变,采用ANTHEPROT5.0软件的GORⅠ法对突变型和野生型蛋白质进行二级结构分析,可见突变蛋白的突变区域部分螺旋结构被转角结构和无规卷曲取代,其二级结构发生了改变.突变LDLR三级结构预测未发现主链结构的变化.结论结果表明.LDLR基因A606T的突变可能是此高胆固醇血症家系的致病原因所在.
목적 검측가족성고담고순혈증(familial hypercholestero-lemia,FH)환자저밀도지단백수체(low density lipoprotein receptor,LDLR)적기인돌변.방법 제취가계중,림상통과전형특정화혈지검측진단위가족성고담고순혈증환자적기인조DNA,수선검측재지단백B100(apoB100)기인R3500Q돌변,이배제가족성apoB100결함증(Familial defective apoB100,FDB).연후용강락취합매련반응(TOUCH-DOWN PCR)확증해기인적계동자화전부18개외현자,재용단련구상다태성(SSCP)방법분석PCR산물,병대전영결과이상자진행DNA측서분석.용ANTHEPROT 5.0연건대돌변LDLR진행이급결구분석,연후대돌변LDLR진행SWISS MODEL재선삼급결구예측.결과 통과SSCP화DNA측서발현해가계환자13호외현자존재A606T적순합돌변,채용ANTHEPROT5.0연건적GORⅠ법대돌변형화야생형단백질진행이급결구분석,가견돌변단백적돌변구역부분라선결구피전각결구화무규권곡취대,기이급결구발생료개변.돌변LDLR삼급결구예측미발현주련결구적변화.결론 결과표명.LDLR기인A606T적돌변가능시차고담고순혈증가계적치병원인소재.
Objective To investigate low density lipoprotein receptor (LDLR)gene mutation in familial hypercholesterolemia (FH) patients. Methods The proband was given clinical diagnosis of homozygous FH based on marked features and blood lipid tests results. After apoB100R3500Q mutation was excluded, the promoter region and all of the 18 exons of LDLR gene were amplified by touch-downpolymerase chain reaction (PCR). The PCR products were analyzed by single-strand conformationalpolymorphism (SSCP). The PCR products with abnormal single strands were sequenced directly. Thesecondary structures of the mutational and wild type proteins were analyzed and compared byANTHEPROT5.0, and then the tertiary structures of the mutant and wild type LDLR were predicted atSWISS MODEL homepage online. Results A homozygous mutation A606T at exon 13 of the patients wasfound by SSCP and confirmed by DNA sequencing. GOR Ⅰ method in ANTHEPROT5.0 indicates that therandom coils and turns would replace some helixes at the mutation site. The online prediction from theSWISS MODEL homepage indicates the backbone structure of the mutant LDLR has no difference from thewild type one. Conclusion The results suggest the A606T mutation of LDLR gene is the cause of the FH inthis pedigree.