Rapid fragile X carrier screening and prenatal diagnosis using a nonradioactive PCR test.
Rapid fragile X carrier screening and prenatal diagnosis using a nonradioactive PCR test.
复制标题
使用非放射性 PCR 检测进行快速脆性 X 携带者筛查和产前诊断。
DOI：
10.1097/00006254-199404000-00007
复制
发表时间：
1994
期刊：
影响因子：
--
通讯作者：
G. Jenkins
中科院分区：
文献类型：
--
作者：
W. Brown;G. Houck;A. Jeziorowska;Faye N. Levinson;Xiao‐hua Ding;C. Dobkin;N. Zhong;J. Henderson;S. Brooks;G. Jenkins
目的
开发一种快速、非放射性的检测方法，使用聚合酶链反应（PCR）能够检测完整的脆性X基因突变、前突变和分辨正常等位基因，并将其应用于产前诊断和脆性X基因携带者筛查。
设计
产前和血液样本PCR分析，并通过直接Southern印迹和细胞遗传学技术进行确认。
设置
样本被送往三级转诊中心的DNA诊断研究实验室。
参与者
有未确诊的精神发育迟滞或已知脆性X综合征家族史的孕妇和对照组。
结果
一种快速，非放射性PCR筛查方案脆性X智力低下-1基因的正常和突变等位基因的开发。对570条对照X染色体的分析表明，CGG重复的众数为30（范围为12至52个重复），计算的杂合性约为80%。未发现过量的纯合性，表明该测试对于正常等位基因分辨率是准确的。此外，还对150名无关孕妇进行了筛查。在已知的脆性X染色体家族中，20名孕妇中有5名被诊断为携带者。在130名女性亲属中诊断出两个新的脆性X家族，这些女性有未诊断的精神发育迟滞家族史，尽管没有发现携带者。对28名携带者进行的产前PCR检测准确地检测出了9名具有完全突变的胎儿。
结论
这种快速、非放射性的PCR方法可以准确分辨正常等位基因，同时检测携带者等位基因和完全突变。通过这种方法，可以有效地筛查有脆性X携带者风险的孕妇，随后对已确定的携带者进行遗传咨询，并提供可靠的产前诊断。
OBJECTIVE
To develop a rapid, nonradioactive test using the polymerase chain reaction (PCR) capable of detecting full fragile X mutations, premutations, and resolving normal alleles and to apply this to prenatal diagnosis and carrier screening of pregnant women at risk for fragile X carrier status.
DESIGN
Prenatal and blood sample PCR analysis with confirmation by direct Southern blotting and cytogenetic techniques.
SETTING
Samples sent to a DNA diagnostic research laboratory at a tertiary referral center.
PARTICIPANTS
Pregnant women with a family history of undiagnosed mental retardation or known fragile X syndrome and controls.
RESULTS
A rapid, nonradioactive PCR screening protocol for the fragile X mental retardation-1 gene for both normal and mutant alleles was developed. Analysis of 570 control X chromosomes showed a modal number of 30 CGG repeats (range, 12 to 52 repeats) and a calculated heterozygosity of approximately 80%. No excess of homozygosity was found, indicating the test was accurate for normal allele resolution. In addition, 150 unrelated pregnant women were screened. Within known fragile X families, five of 20 pregnant women were diagnosed as carriers. Two new fragile X families were diagnosed among relatives of 130 females with family histories of undiagnosed mental retardation, although no carriers were identified. Prenatal PCR testing of 28 carriers accurately detected nine fetuses with full mutations.
CONCLUSIONS
This rapid, nonradioactive PCR protocol allows accurate resolution of normal alleles as well as simultaneous detection of carrier alleles and full mutations. With this approach, efficient screening of pregnant women at risk for fragile X carrier status, subsequent genetic counseling of identified carriers, and reliable prenatal diagnosis can be offered.