CAJ | 학술논문

目的探讨2例临床确诊的湖北籍FH患者的LDLR基因突变状况,为FH的基因诊断提供依据.方法收集2例临床确诊的FH患者及其父母血脂检测指标等临床资料,通过PCR扩增LDLR基因的1～18个外显子和内含子区域,再将扩增产物进行正、反双向核苷酸序列分析,并与GenBank中LDLR基因的正常序列对比找出突变后,结合FH先证者的临床表型证实致病突变的类型.结果氧化酶法测定1号、2号FH先证者血浆TC,分别为12.79、11.98 mmol/L;经核苷酸序列分析,其ApoB100基因涵盖的3 500～3 531区域均未见突变;LDLR基因均为复合杂合突变,1号FH先证者LDLR基因第4外显子的665位碱基G>T为杂合错义突变,且该突变为新的点突变,第9内含子的1 358+32位碱基C>T突变也为新的点突变,并均由其父母遗传.2号先证者第9外显子1 257位碱基C>A突变导致终止密码子提前出现,但其核苷酸改变与比利时报道的C>G不同,第13外显子检测到1 879位碱基G>A杂合错义突变,且分别来源于其父母.结论 2例FH先证者均存在LDLR基因复合杂合突变,1号FH先证者的第4外显子665位碱基G>T和第9内含子1 358+32位碱基C>T、2号FH先证者的第9外显子1 257位碱基C>A突变均为新突变,这可能是导致FH的分子机制.
목적 탐토2례림상학진적호북적FH환자적LDLR기인돌변상황,위FH적기인진단제공의거.방법 수집2례림상학진적FH환자급기부모혈지검측지표등림상자료,통과PCR확증LDLR기인적1～18개외현자화내함자구역,재장확증산물진행정、반쌍향핵감산서렬분석,병여GenBank중LDLR기인적정상서렬대비조출돌변후,결합FH선증자적림상표형증실치병돌변적류형.결과 양화매법측정1호、2호FH선증자혈장TC,분별위12.79、11.98 mmol/L;경핵감산서렬분석,기ApoB100기인함개적3 500～3 531구역균미견돌변;LDLR기인균위복합잡합돌변,1호FH선증자LDLR기인제4외현자적665위감기G>T위잡합착의돌변,차해돌변위신적점돌변,제9내함자적1 358+32위감기C>T돌변야위신적점돌변,병균유기부모유전.2호선증자제9외현자1 257위감기C>A돌변도치종지밀마자제전출현,단기핵감산개변여비리시보도적C>G불동,제13외현자검측도1 879위감기G>A잡합착의돌변,차분별래원우기부모.결론 2례FH선증자균존재LDLR기인복합잡합돌변,1호FH선증자적제4외현자665위감기G>T화제9내함자1 358+32위감기C>T、2호FH선증자적제9외현자1 257위감기C>A돌변균위신돌변,저가능시도치FH적분자궤제.
Objective To determine LDLR gene mutation in 2 clinically diagnosed FH patients from Hubei province and provide basis for gene diagnosis of FH.Methods Clinical data of 2 FH patients and their parents were collected.The promoter region and exon 1 to exon 18 region of LDLR gene were amplified through PCR and the amplified products were analyzed by forward and reverse DNA sequencing.The mutations were identified after comparison with LDLR gene sequence in GenBank.The pathogenic gene mutations were confirmed according to both genotype and phenotype of FH probands.Results The levels of plasma TC of two probands were 12.79 and 11.98 mmol/L.respectively.No gene mutations were detected in region 3 500 to 3 531 of ApoB100. The mutations of LDLR gene were compound heterozygous mutations. The novel mutation 665G > T detected in the exon 4 of No. 1 proband's LDLR gene was heterozygous missense mutation. The novel mutation 1 358 +32C > T was detected in the exon 9 of No. 1 proband's LDLR gene.The mutations 665G > T ( paternal origin) and 1 358 + 32C > T ( maternal origin) were inherited from the parents. A novel mutation 1 257 C > A was detected in the exon 9 of No. 2 proband's LDLR gene, resulting the presence of a premature termination codon, which was different from 1 257 C > G reported in Belgium.Another heterozygous missense mutation 1 879 G > A was detected in exon 13. They were derived from paternal origin and maternal origin, respectively. Conclusions There are three novel gene mutations:665G >T, 1 358 +32C > T, 1 257C > A found in two probands with compound heterozygous mutations in LDLR respectively. They maybe play a potential role in FH pathogensis.