UNITY Prenatal Blood Test Accurate at Diagnosing CF, Other Hereditary Diseases, Study Shows

Patricia Inácio, PhD avatar

by Patricia Inácio, PhD |

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The UNITY prenatal test is highly sensitive and accurate for detecting hereditary diseases such as cystic fibrosis (CF), spinal muscular atrophy (SMA), sickle cell disease, and thalassemias, a new study reports.

Developed by BillionToOne, the non-invasive test uses maternal blood to detect CF and other hereditary diseases in fetuses. The test assesses cell-free DNA that’s released by the fetus to understand whether specific mutations are present.

The findings were reported in the study, “A novel high-throughput molecular counting method with single base-pair resolution enables accurate single-gene NIPT,” which was published in the journal Nature Scientific Reports.

According to the American College of Obstetricians and Gynecologists, every pregnant woman should be screened for CF, SMA, sickle cell disease, and thalassemias. Prenatal screening is performed on the parents. However, even for the 10%–15% of mothers who test positive for these conditions, there is less than 5% risk for their baby to have the disease. To reach a final diagnosis, the father must be tested as well, which can be time-consuming and costly.

The UNITY test takes five to 10 days, with less work for clinicians and faster results that save time and money than traditional prenatal screening, which can take up to 12 weeks to process, according to BillionToOne.

The test uses a recently developed molecular technique — called Quantitative Counting Template (QCT) — that is able to count single DNA molecules, and therefore detect the rare mutations that are present in the cell-free DNA found in maternal blood.

The team started by testing the accuracy of the QCT technique by using synthesized DNA molecules. From 1,000 preclinical samples, the researchers determined that the technique was sensitive and highly accurate — with a sensitivity (the ability of a test to correctly identify those with the disease) and a specificity of above 98%.

Moreover, from 208 clinical samples obtained from healthy pregnant women, they found that prenatal testing was 100% consistent with analysis performed on the newborns.

“All NIPT [non-invasive prenatal testing] results were 100% concordant with the newborn genotype, even in challenging samples with fetal fractions as low as 5%,” the researchers wrote.

Overall, the data showed that “BillionToOne’s molecular counter improves the resolution of cell-free DNA testing over a 1,000-fold compared to traditional NIPT methods,” Oguzhan Atay, PhD, CEO and co-founder of BillionToOne, said in a news release. “We are excited to publish our detailed methodology and results that showcase accurate single-gene NIPT calls that underlie UNITY.”

David Tsao, PhD, chief technical officer and co-founder of BillionToOne, and the study’s lead author, added: “QCT molecular counting platform has the potential to serve a wide range of unmet clinical needs…. With UNITY, we are able to screen for most common genetic disorders directly in the baby from maternal blood alone.”

Through the BillionToOne’s early access program, the test is currently available at selected clinics in the U.S., Germany, Austria, and the Netherlands. The cost can be reimbursed by most insurance providers, including Medicaid. More information on this prenatal test can be found at www.unityscreen.com.

Of note, the study was partly funded by BillionToOne, and some of the researchers have links to the company.