眼皮肤白化病Ⅱ型产前基因诊断二例  

Prenatal genetic diagnosis for two Chinese families affected with oculocutaneous albinism type Ⅱ

作　　者：胡浩[1] 王华[1] 贾政军[1] 谢琼[1] 

机构地区：[1]湖南省妇幼保健院遗传优生科,长沙410008

出　　处：《中华医学遗传学杂志》2014年第4期424-427,共4页Chinese Journal of Medical Genetics

基　　金：湖南省社会科技发展支撑计划（2009SK3048）

摘　　要：目的对生育过眼皮肤白化病（oculocutaneous albinism，OCA）息儿的2个家系进行基因诊断分型，并在此基础上提供产前基因诊断。方法采用PCR扩增先证者OCAl型疾病相关TYR基因的所有5个编码外显子和OCA2型疾病相关P基因的所有23个编码外显子，PCR产物直接测序，在确定致病突变的基础上对家系成员进行综合分析。结果两例OCA先证者均未检测到TYR基因的致病突变，但均携带P基因的复合杂合突变，因此确定2例均为OCA2型患者。P基因共检测到4种突变：C．406C〉T、c．535A〉G、c．808-2A〉G和c．2180T〉C，其中c．535A〉G和c．808-2A〉G为新突变。2个家系的第1次产前诊断均提示胎儿基因型与先证者一致，家属选择终止妊娠。第2次产前基因诊断，2个家系中1例胎儿为P基因c．808-2A〉G携带者，另1例为P基因野生型携带者。两名孕妇均继续妊娠至足月分娩，新生儿随访均正常。结论应用基因检测可为眼皮肤白化病患者提供确切的临床分型，并在此基础上提供有效的产前基因诊断。Objective To perform genotyping analysis and subsequent prenatal genetic diagnosis for two families affected with oculocutaneous albinism （OCA）. Methods Direct sequencing of TYR and P genes was performed in two albino probands. Family members were screened for corresponding mutant alleles. Prenatal genetic diagnoses were performed at early pregnancy by chorionic villus sampling （CVS） at mid-pregnancy through amniocentesis. Results No mutations were detected in the TYR gene in either probands, whereas 4 heterozygous mutations of the P gene were found, namely c. 406C〉T, c. 535A〉G, c. 808-2A〉G and c. 2180T〉C, among which c. 53SANG and c. 808-2A〉G were novel. In the first round prenatal genetic testing, both fetuses were found to have the same genotypes as the probands. Both families had decided to terminate the pregnancy after genetic counseling. In the second round testing, neither of the fetuses was found to be affected by genotyping. The pregnancies continued and two healthy fetuses were born. Conclusion OCA can be classified by genotyping, with which reliable prenatal diagnosis and feasible genetic counseling may be provided.

关 键 词：白化病2型 P基因 测序 突变 产前基因诊断 

分 类 号：R596.1[医药卫生—内科学]