Study of the Day: Sequencing Fetal DNA With a Simple Blood Test

New research shows how blood from the expectant mother and saliva from the father are enough to safely sequence the whole fetal genome.

Study of the DayDanielW/Shutterstock

PROBLEM: Though scientists have long known that a pregnant woman's blood plasma contains cell-free DNA from her developing fetus, they've had trouble figuring out which genetic variants get passed on from mother to child. As a result, doctors have had to resort to invasive procedures, such as tapping the protective fluid sac in the mother's womb, to detect suspected abnormalities.

METHODOLOGY: Geneticists led by Jacob O. Kitzman used saliva specimens from expectant fathers and blood samples from mothers who were about 18 weeks pregnant. To non-invasively determine the whole genome sequence of the fetuses, they used advanced biostatistics to combine the genome sequencing of the parents, genome-wide maternal haplotyping (grouping of genetic variants), and deep sequencing of maternal plasma DNA. They then checked the accuracy of their genetic predictions by collecting umbilical cord blood at birth.

RESULTS: The researchers successfully picked out the parts of the fetal genetic material inherited from each parent with over 98 percent accuracy. They also detected 39 of 44 new genetic variations not shared with either parent.

CONCLUSION: Parental DNA samples -- blood from the mother, saliva from the father -- contain enough genetic information to map a fetus' genome.

IMPLICATION: A safe, affordable, and comprehensive genetic screen during pregnancy for thousands of potential conditions may be in the offing. As co-author Jay Shendure puts it in a statement: "This work opens up the possibility that we will be able to scan the whole genome of the fetus for more than 3,000 single-gene disorders through a single, non-invasive test."

SOURCE: The full study, "Noninvasive Whole-Genome Sequencing of a Human Fetus," is published in the journal Science Translational Medicine.

Presented by

Hans Villarica writes for and produces The Atlantic's Health channel. His work has appeared in TIME, People Asia, and Fast Company.

What Happened to the Milky Way?

Light pollution has taken away our ability to see the stars. Can we still save the night sky?

Join the Discussion

After you comment, click Post. If you’re not already logged in you will be asked to log in or register with Disqus.

Please note that The Atlantic's account system is separate from our commenting system. To log in or register with The Atlantic, use the Sign In button at the top of every page.

blog comments powered by Disqus

Video

What Happened to the Milky Way?

Light pollution has taken away our ability to see the stars. Can we still save the night sky?

Video

The Faces of #BlackLivesMatter

Scenes from a recent protest in New York City

Video

Desegregated, Yet Unequal

A short documentary about the legacy of Boston busing

Video

Ruth Bader Ginsburg on Life

The Supreme Court justice talks gender equality and marriage.

Video

Social Media: The Video Game

What if the validation of your peers could "level up" your life?

Video

The Pentagon's $1.5 Trillion Mistake

The F-35 fighter jet was supposed to do everything. Instead, it can barely do anything.

More in Health

Just In