二尼曼匹克病家系NPC1和NPC2基因突变检测分析

Detection of the genotypes of the NPC1 and NPC2 genes for adult patients with Niemann-Pick's disease

目的:二C型尼曼匹克病患者家系,对其进行NPC1和NPC2基因测序分析基因型与表型关系。方法:采患者及家系外周血基因组DNA,根据人类基因组数据库NC_000018(NPC1)及NG_007117(NPC2)基因序列设计引物分别扩增25个外显子和5个外显子区域,产物经过回收纯化,采用直接测序进行突变检测,测序结果应用DNAman等软件进行序列分析,对于异常片段进行重新扩增测序,验证结果可靠性。结果:二例患者均在NPC1基因发现杂合子位点A644G(H215R),导致第215位氨基酸由His突变为Arg;18号外显子发现一个杂合位点N931N(C2793T),氨基酸编码没有改变,家系成员未发现上述基因位点突变。结论:二尼曼匹克患者具有典型尼曼匹克临床特征,在基因水平上也发现相关基因突变位点,但在遗传上与家系成员相关不大。因此对于尼曼匹克患者或存在其他致病因素。

Objective To detect the genotypes of the NPCI and NPC2 genes for old adult patients with Niemann-Pick＇s disease, and to analyze the relationship between phenotype and genotype. Methods The genomic DNA of the patient was extracted from peripheral blood, and the PCR primers of the 25 exons of the NPCI and 5 exons of the NPC2 genes were designed according to the genbank sequence of NC_000018 and NG_007117 respectively. Each PCR product was purified and sequenced. Results Both patients carried heterozygotes polymorphisms in the coding region including A644G （H215R） and C2793T （N931N） in NPC1 gene. No other heterozygotes and homozygotes were found in NPC1 and NPC2 gene. Conclusions Patients that present typical phenotypes of Niemann-piek＇s disease without carrying related mutations or new mutations may caused by other unknown factors.