Stanford Center for Biomedical Ethics, Department of Pediatrics, Division of Genetics, Stanford University, Stanford, CA, USA.
Obstet Gynecol Surv. 2011 Jul;66(7):431-42. doi: 10.1097/OGX.0b013e31822dfbe2.
Cell-free fetal nucleic acids circulating in the blood of pregnant women afford the opportunity for early, noninvasive prenatal genetic testing. The predominance of admixed maternal genetic material in circulation demands innovative means for identification and analysis of cell-free fetal DNA and RNA. Techniques using polymerase chain reaction, mass spectrometry, and sequencing have been developed for the purposes of detecting fetal-specific sequences, such as paternally inherited or de novo mutations, or determining allelic balance or chromosome dosage. Clinical applications of these methods include fetal sex determination and blood group typing, which are currently available commercially although not offered routinely in the United States. Other uses of cell-free fetal DNA and RNA being explored are the detection of single-gene disorders, chromosomal abnormalities, and inheritance of parental polymorphisms across the whole fetal genome. The concentration of cell-free fetal DNA may also provide predictive capabilities for pregnancy-associated complications. The roles that cell-free fetal nucleic acid testing assume in the existing framework of prenatal screening and invasive diagnostic testing will depend on factors such as costs, clinical validity and utility, and perceived benefit-risk ratios for different applications. As cell-free fetal DNA and RNA testing continues to be developed and translated, significant ethical, legal, and social questions will arise that will need to be addressed by those with a stake in the use of this technology.
Obstetricians & Gynecologists and Family Physicians Learning Objectives: After participating in this activity, physicians should be better able to evaluate techniques and tools for analyzing cell-free fetal nucleic acids, assess clinical applications of prenatal testing, using cell-free fetal nucleic acids and barriers to implementation, and distinguish between relevant clinical features of cell-free fetal nucleic acid testing and existing prenatal genetic screening and diagnostic procedures.
孕妇血液中循环的无细胞胎儿核酸为早期、非侵入性产前遗传检测提供了机会。混合的母体遗传物质在循环中占主导地位，这就需要创新的方法来识别和分析无细胞胎儿 DNA 和 RNA。已经开发了使用聚合酶链反应、质谱和测序的技术，用于检测胎儿特异性序列，如父系遗传或新生突变，或确定等位基因平衡或染色体剂量。这些方法的临床应用包括胎儿性别鉴定和血型鉴定，虽然目前在美国尚未常规提供，但这些方法已经商业化。正在探索无细胞胎儿 DNA 和 RNA 的其他用途包括检测单基因疾病、染色体异常以及整个胎儿基因组中亲本多态性的遗传。无细胞胎儿 DNA 的浓度也可能为与妊娠相关的并发症提供预测能力。无细胞胎儿核酸检测在现有的产前筛查和侵入性诊断检测框架中所扮演的角色将取决于成本、临床有效性和实用性以及不同应用的感知获益风险比等因素。随着无细胞胎儿 DNA 和 RNA 检测的不断发展和转化，将出现重大的伦理、法律和社会问题，需要对这项技术的使用者进行解决。
妇产科医师和家庭医生学习目标：参加完本次活动后，医生应能够更好地评估分析无细胞胎儿核酸的技术和工具，评估使用无细胞胎儿核酸进行产前检测的临床应用、实施的障碍以及无细胞胎儿核酸检测与现有产前遗传筛查和诊断程序的相关临床特征之间的区别。
