两个亨廷顿病家系的基因诊断和产前诊断  

Genetic testing and prenatal diagnosis of two pedigrees affected with Huntington disease

作　　者：任依琳 代鹏[1] 陈晨[1] 段会坤 孔祥东[1] Ren Yilin;Dai Peng;Chen Chen;Duan Huikun;Kong Xiangdong(Center of Genetics and Prenatal Diagnosis,Department of Obstetrics and Gynecology,the First Affiliated Hospital of Zhengzhou University,Zhengzhou,Henan 450052,China)

机构地区：[1]郑州大学第一附属医院遗传与产前诊断中心妇产医学部,450052

出　　处：《中华医学遗传学杂志》2021年第5期446-449,共4页Chinese Journal of Medical Genetics

基　　金：国家重点研发计划(2018YFC1002203)。

摘　　要：目的对2个亨廷顿病(Huntington’s disease,HD)家系进行IT15基因的变异分析,为患者的临床诊断及家系的遗传咨询和产前诊断提供依据。方法采集两个家系成员的外周静脉血样和胎儿绒毛或羊水样本,提取基因组DNA,采用PCR和毛细管电泳法检测先证者和家系成员IT15基因(CAG)n的重复数目,并为家系中的3名孕妇提供产前诊断。结果2个家系先证者(CAG)n重复数目大于40,确定为亨廷顿病患者。家系1中另2名家系成员和家系2的另1名家系成员的IT15基因(CAG)n重复数目大于40,携带完全外显的等位基因,但均未发病,为症状前患者。产前基因诊断结果显示,家系1中的2名胎儿IT15基因(CAG)n重复数目分别为(16,19)/(18,19),均携带正常的等位基因;家系2胎儿(CAG)n重复数目为(15,41),胎儿携带异常的等位基因。结论对于HD家系成员行IT15基因检测和产前诊断,为患者的临床诊断及家系的遗传咨询提供了依据。Objective To explore the genetic basis for two Chinese pedigrees affected with Huntington disease and provide prenatal diagnosis for them.Methods Peripheral venous blood samples were collected from the probands.PCR and capillary gel electrophoresis were used to determine the number of CAG repeats in their IT15 gene.Pre-symptomatic testing was offered to their children and relatives,and prenatal diagnosis was provided to three pregnant women from the two pedigrees.Results The two probands,in addition with three asymptomatic members,were found to have a(CAG)n repeat number greater than 40.Upon prenatal diagnosis,the numbers of CAG repeats in two fetuses from pedigree 1 were determined as(16,19)and(18,19),both were within the normal range.A fetus from pedigree 2 was found to have a CAG repeat number of(15,41),which exceeded the normal range.Conclusion Genetic testing can facilitate the diagnosis of HD and avoid birth of further affected children.

关 键 词：亨廷顿病 IT15基因 (CAG)n重复 基因诊断 产前诊断 

分 类 号：R742.2[医药卫生—神经病学与精神病学]