Noninvasive Prenatal Diagnosis of Fetal Aneuploidies: Review of Current Status in Taiwan

Ming Chen

《The Changhua Journal of Medicine》 11卷2期 (2013/12) Pp. 69-73

並列摘要

Non-invasive prenatal diagnosis (NIPD) is considered the ”Holy Grail” of prenatal genetic diagnosis. Tremendous efforts have been made since the discovery of the existence of cell-free fetal or placental DNA in the plasma of pregnant women in 1997 (by Dennis YM Lo, then in the UK, now in HK). However, due to the ultra-high standard of the demand for sensitivity and accuracy that is of paramount importance in prenatal diagnosis (because it involves a ”life-or-death” scenario when deciding if the pregnancy should continue or be terminated), most technologies failed to respond to this demand until the introduction of next-generation sequencing (NGS). NGS became a clinical reality in the past two years for detecting fetal trisomies and a few monogenic disorders by institutions and companies based in the US and China. NIPD is expected to replace invasive prenatal diagnosis (IPD) eventually. At the current stage, clinical tests are available for fetal aneuploidy disorders, for example, trisomy 13 (Patau syndrome), trisomy 18 (Edwards syndrome) and trisomy 21 (Down syndrome). Definitive diagnoses for these aneuploidies currently rely on invasive procedures, such as chorionic villus sampling, amniocentesis and cord blood sampling, and are associated with a risk of fetal miscarriage. Fetal DNA has been found in maternal plasma, existing as a minor fraction among a high background of maternal DNA. Therefore, quantitative analysis of plasma DNA may provide a new opportunity for developing noninvasive prenatal testing (NIPT) for fetal aneuploidy. Next-generation sequencing (NGS; or so-called high-throughput sequencing) is a novel, rapid sequencing method that can simultaneously analyze large amounts of DNA. By referring to the reference human genome, the re-sequenced DNA fragments can be mapped to the corresponding chromosomes, and thus the DNA fragments from a specific chromosome can be counted. A brief review of NIPT and its current status in Taiwan is provided.

並列關鍵字

Non-invasive prenatal diagnosis (NIPD) ； non-invasive prenatal testing (NIPT) ； next-generation sequencing (NGS) ； trisomy