A new DNA test will look for 190 diseases in your newborn’s genetic code

Using a swab of saliva from a newborn’s cheek, a new DNA test will probe the baby’s genes to search for 193 genetic diseases, like anemia, epilepsy, and metabolic disorders.

The $649 test is meant for healthy babies, as a supplement to existing screening tests.

In the US, the government recommends a newborn screening test that looks for a minimum of 34 disorders (though some states have additional requirements as well). The standard test involves a small sample of blood taken from a baby’s heel.

Eric Schadt, CEO of Sema4, the company behind the test, says some parents may want more information about their child’s genes than this standard testing delivers. Some people suffer for years before getting a proper diagnosis for some of the diseases that his company’s test covers, he says.

“If you can, at birth, canvass some of the most common disorders, you get a better understanding of the health of your child,” Schadt says. “We think parents want the best for their children and are going to do whatever they can so that their child can have the healthiest life possible.”

All the conditions the Sema4 test looks for—it uses DNA sequencing to examine a subset of genes, rather than the whole genome—have some kind of treatment already available. The test also analyzes how a baby is likely to respond to 38 medications commonly prescribed in early childhood.

Schadt says anyone can order the Sema4 test online, and a doctor with the company approves it. The test isn't covered by insurance yet. 

The trouble is, even if a baby has a mutation in a gene, it could take years for symptoms to appear. And sometimes a child can carry a mutation but never develop the corresponding disease. That’s one reason DNA sequencing isn’t yet routine for children and adults who are currently healthy.

That raises a big question: is a test like Sema4’s always a good thing?

“For many families, this is the kind of thing that can open up a can of worms where it doesn’t end up necessarily benefiting the parent or child,” says Laura Hercher, a geneticist at Sarah Lawrence College.

In some cases, the results of the test could cause anxiety and confusion for parents and lead to unnecessary tests and procedures for children, she says: “You put parents in a terrible position, because they don’t know if they should wait until the child is sick to do in some cases draconian treatments.”