摘要
目的 检测中国汉族家族性高胆固醇血症 (familial hypercholesterolemia,FH)大家系低密度脂蛋白受体 (low density lipoprotein receptor,L DL R)基因突变 ,探讨 FH发病的分子机理。方法 首先采用聚合酶链反应 -限制性片段长度多态性 (polymerase chain reaction- restriction fragment lengthpolymorphism,PCR- RFL P)技术检测载脂蛋白 B1 0 0 (apo B1 0 0 )基因 Q35 0 0 R突变 ,排除家族性 apo B1 0 0 缺陷症 ,再采用 PCR扩增结合核苷酸序列分析检测 1例临床诊断为 FH纯合子患儿及其家系成员 L DL R基因启动子和全部 18个外显子片段 ,结果与 Gen Bank公布的该基因正常序列对比找出突变 ,并在家系其他成员中证实该突变。结果 该患儿 L DL R基因第 3内含子剪接供体处存在 IN 5′GT→AT纯合剪接突变 ,并且在家系中得到证实 ,一级和二级亲属中各发现 2例相同位点和相同形式的杂合子 ,其基因型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 apo B1 0 0 Q35 0 0 R突变。结论 发现 L DL R基因第 3内含子 G→ A纯合剪接突变 ,可能是该 FH家系发病的分子基础 ;检测该突变对临床干预和遗传指导有参考价值。
ObjectiveTo identify the mutation of low density lipoprotein receptor( LDLR ) gene in a large Chinese family with familial hypercholesterolemia(FH) and make a discussion on the pathogenesis of FH at the molecular level. MethodsInvestigations were made on a patient with the clinical phenotype of homozygous FH and his parents for mutations of promoter and all 18 exons of LDLR gene. Screening was carried out using Touch-down PCR and agarose gel electrophoresis, combined with DNA sequence analysis. The results were compared with the normal sequences in GenBank and FH database (www.ucl.uk/fh) to find the mutation. Then the mutation was identified in other members of the family. In addition, the authors screened the apolipoprotein B_ 100 ( apoB_ 100 ) gene for known mutations (R3500Q) that cause familial defective apoB_ 100 (FDB) by PCR-RFLP. ResultsA novel homozygous INⅢ5′GT→AT mutation in the splice donor of LDLR intron 3 was detected in the homozygote propositus with FH. The mutation was also identified in four heterozygous carriers in his family. No mutations R3500Q of apoB_ 100 were observed. ConclusionA homozygous G→A splice mutation in LDLR gene was first reported. The change of the splice donor in LDLR intron 3 may cause skipping of exon 3, which is responsible for FH. Perhaps it is a particular pathogenesis for Chinese people.
出处
《中华医学遗传学杂志》
CAS
CSCD
2004年第1期14-18,共5页
Chinese Journal of Medical Genetics
基金
北京市自然科学基金 (70 32 0 1 2 )
首都医科大学基础临床合作基金 (0 2 JL1 9)~~
