中文摘要：

目的建立低密度脂蛋白受体（LDLR）基因全长cDNA序列分析方法并对1例家族性高胆固醇血症（FH）患儿进行基因检测。方法设计7对LDLR基因cDNA引物并验证;对1例临床诊断为FH的患儿进行家系调查和临床体检,提取外周血DNA和RNA,DNA扩增结合测序分析LDLR基因并找出其突变位点;RNA经PCR反转录为cDNA后扩增LDLR基因,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位点后与传统DNA测序方法结果比对。结果 LDLR基因全长cDNA序列分析方法检测LDLR基因为2 583个碱基,与标准序列完全一致;本例患儿确诊为＂FH纯合子＂,cDNA测序结果与传统DNA测序结果相符,均为第2外显子终止突变和第6外显子点突变及框移突变。结论 LDLR基因全长cDNA序列分析法检测FH患儿突变,与传统DNA方法检测结果相符,可为FH的基因诊断提供新的方法依据。

英文摘要：

Objective To establish the whole cDNA sequencing method for analyzing the mutation of low-density lipoprotein receptor（LDLR） gene in a child patient with familial hypercholesterolemia（FH）. Methods Seven pairs of primers for LDLR gene were designed and verified. One child patient with FH was performed medical examination,and the family was surveyed. The patient＇s peripheral blood sample was collected,and DNA and RNA were isolated. DNA was directly amplified by PCR with primers for LDLR gene and the amplified product was sequenced to find mutation sites. RNA was first reversed to be cDNA,then amplified by PCR with primers for LDLR gene,and the amplified product was performed sequencing analysis. The mutation sites were identified by comparing with normal LDLR gene sequence in GenBank. Finally the results obtained by the whole cDNA sequencing method were compared with the results by traditional DNA sequencing. Results Analysis for whole LDLR cDNA sequencing showed that LDLR gene contained 2 583base pairs,which was in concordance with the standard sequence of LDLR gene. The child patient was diagnosed as FH homozygote.The results obtained by the whole cDNA sequencing method were consistent with the results by traditional DNA sequencing,that is,both of them contained the terminator codon mutation in exon 2 and the single base substitution and the frame shift mutations in exon 6.Conclusion The whole cDNA sequencing method could be used to detect the mutations of LDLR gene in FH patients,which may provide the evidence for the gene diagnosis of FH.