基于荧光聚合酶链反应的脆性X综合征产前筛查技术的建立

A Fluorescent Polymerase Chain Reaction-based Prenatal Screening Assay for Fragile X Syndrome

目的建立针对脆性X综合征FMR1基因CGG重复数的快速产前检测技术方法,用于基于人群的筛查。方法采用荧光PCR法对356名孕妇进行产前FMR1基因CGG重复数检测。结果本方法可检测CGG重复数小于130的携带者,共275例(77.25%)毛细管电泳结果显示为2组峰,提示为杂合型基因型,可明确诊断。81例(22.75%)仅见到一组峰,提示可能为纯合子,也可能为CGG重复数高于130的携带者。结论基于荧光PCR的检测技术,临床上可实现近80%孕妇FMR1基因CGG重复数精确、快速的初筛,剩余病例的明确诊断尚需其他技术辅助。

Objective To establish an assay for detecting CGG repeats in FMR1 gene efficiently, and ascertain this assay as tools for population-based screening. Method 365 pregnancies in routine prenatal screening were recruited for genotyping by using fluorescence polymerase chain reaction (F-PCR). Results The F-PCR accurately detected permutation alleles up to 130 CGG repeats. 77.25% of the 365 pregnant women enrolled in routine prenatal screening were carrying heterozygous alleles. Because of the limitation of the approach, 22.75% of the samples with single peak in electrophoresis can not be diagnosed. Conclusions The F-PCR assay developed in this study was a reliable and efficient first-step approach for fragile X syndrome in clinical testing and for prenatal purpose, but for those carrying up to 130 repeats and homozygous individuals further tests are needed.