Next-generation sequencing and the impact on prenatal diagnosis

The advent of affordable and rapid next-generation sequencing has been transformative for prenatal diagnosis. Sequencing of cell-free DNA in maternal plasma has enabled the development of not only a highly sensitive screening test for fetal aneuploidies, but now definitive noninvasive prenatal diagnosis for monogenic disorders at an early gestation. Sequencing of fetal exomes offers broad diagnostic capability for pregnancies with unexpected fetal anomalies, improving the yield and accuracy of diagnoses and allowing better counseling for parents. The challenge now is to translate these approaches into mainstream use in the clinic. Areas covered: Here, the authors review the current literature to describe the technologies available and how these have evolved. The opportunities and challenges at hand, including considerations for service delivery, counseling, and development of ethical guidelines, are discussed. Expert commentary: As technology continues to advance, future developments may be toward noninvasive fetal whole exome or whole genome sequencing and a universal method for noninvasive prenatal diagnosis without the need to sequence both parents or an affected proband. Expansion of cell-free fetal DNA analysis to include the transcriptome and the methylome is likely to yield clinical benefits for monitoring other pregnancy-related pathologies such as preeclampsia and intrauterine growth restriction.