A New Era in Prenatal Diagnosis: The Use of Cell-Free Fetal DNA in Maternal Circulation for Detection of Chromosomal Aneuploidies

摘要: Prenatal screening for chromosomal aneuploidies is a fundamental part of routine obstetric care in most countries. Typically, maternal age, weight, ethnicity, serum biomarkers (including pregnancy-associated plasma protein A, human chorionic gonadotropin, α-fetoprotein, inhibin and estriol), sonographic features (i.e., nuchal translucency) are included risk algorithm to determine the probability fetus being affected. Pregnant women identified as at high according prenatal screen can then undergo invasive procedures, such amniocentesis villus sampling, confirm diagnosis. Current prenatal-screening methods able identify approximately 90% pregnancies affected by trisomy 21 (Down syndrome) false-positive rate 5%. Given that prevalence generally quite low, 5% means large number with unaffected putting an unnecessary miscarriage. The discovery fetal cell-free DNA pregnant 14 years ago opened up possibility identifying abnormalities noninvasively, through single blood sample. Approximately 10% circulation origin, this property was initially exploited rhesus D status sex unborn fetus. advent next-generation sequencing, however, has allowed detection aneuploidies, including 21, from blood. In brief, proportion chromosome molecules measured directly; increase above predetermined threshold indicative 21. clinical performance noninvasive test been promising, recent studies having shown diagnostic sensitivity 100% specificity 98%–99%, compared full karyotyping means. When used second-tier procedure, technology also …