疑似脆性X综合征患者家系基因筛查和产前诊断  

Genetic screening and prenatal diagnosis for high risk families of Fragile X syndrome

作　　者：席惠[1] 张亚南[1] 卿礼艳 康怀兴[2] 段然慧[2] 贾政军[1] 王华[1] Xi Hui1 , Zhang Yanan1 , Qin Liyan1 , Kang Huaixing2 , Duan Ranhui2 , Jia Zhengjun1 , Wang Hua1(1.Center of Hunan Provincial Prenatal Diagnosis, Hunan Maternal and Child Health Hospital, Changsha, Hunan 410008, China ; 2.Research Center of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan 410078, China)

机构地区：[1]湖南省产前诊断中心、湖南省妇幼保健院,长沙410008 [2]中南大学生命科学院医学遗传学研究中心,长沙410078

出　　处：《中华医学遗传学杂志》2018年第5期653-656,共4页Chinese Journal of Medical Genetics

基　　金：湖南省科技厅自然科学基金（2017JJ3144）;湖南省科技厅创新平台与人才计划（2015TP2029）

摘　　要：目的探索脆性x综合征基因筛查在临床的应用价值。方法对6个病因不明智力低下家系采用基于三引物PCR检测方法的国产试剂盒进行脆性X综合征筛查，同时采用甲基化PCR＋Southern印迹杂交校验检测结果。结果家系1和家系6筛查结果阳性。家系1中先证者和母亲均存在一条甲基化的全突变等位基因。胎儿遗传了母亲的全突变等位基因；家系6先证者为部分甲基化的前突变和全突变的嵌合体，其姐姐携带甲基化全突变等位基因，母亲为前突变等位基因携带者，父亲和胎儿均正常。家系2-5筛查结果阴性并与甲基化PCR结果一致。结论通过对疑似患者进行脆性X综合征的基因筛查，进而进行基因诊断和产前诊断，不仅结果准确可靠而且有效的降低了检测成本，是预防该病经济高效的方法。Objective To assess the value of genetic testing for Fragile X syndrome （FXS）. Methods A domestically made diagnostic kit based Tri-primer-PCR method was used to detect mutations of the FMR1 gene among 6 pedigrees with unexplained intellectual disability. The results were verified by methylation PCR and Southern blotting. Results Pedigrees 1 and 6 were positive for the screening. In pedigree 1, a full-mutation allele with methylation was identified in the proband and his mother, which was passed on to the fetus. In pedigree 6, the proband was mosaic for a full-mutation allele and a pre-mutation allele. His sister was asymptomatic with a full-mutation. His mother carried pre-mutation allele, while his father and sister＇s baby were normal. The number of CGG repeats of the pedigrees 2 to 5 were in the normal range. Conclusion Genetic testing can provide an effective way to prevent FXS caused by FMR1 mutations and enable prenatal diagnosis for families with a high risk for the disease.

关 键 词：脆性X综合征 智力低下 FMR1基因 基因筛查 

分 类 号：R714.55[医药卫生—妇产科学] R440[医药卫生—临床医学]