Newcomer BillionToOne launches prenatal blood screener for cystic fibrosis, SMA and sickle cell

Following its $15 million series A round earlier this year, BillionToOne has launched its first product for commercial and clinical use—a prenatal screening test for cystic fibrosis, spinal muscular atrophy and sickle cell disease.

The company’s molecule-counting diagnostic test, Unity, searches for cell-free fetal DNA using blood drawn from the mother. The Menlo Park, California-based BillionToOne is planning a limited initial commercial launch before a wider rollout set for later this year.

After the mother is found to be a carrier of the related recessive genes, the Unity test checks to determine if the baby is at high risk for inherited disorders. The entire process takes up to two weeks, compared to 12 weeks or more for traditional carrier screening involving both parents, according to the Y Combinator alum. 

BillionToOne also bills for the test through existing insurance codes for carrier testing, which are reimbursed by most insurance providers, as well as Medicaid. The American College of Obstetricians and Gynecologists recommends that every pregnant woman be screened for her carrier status for cystic fibrosis, SMA, sickle cell disease and thalassemias, the company said.

However, some non-invasive prenatal tests may exclude single-gene inherited disorders such as cystic fibrosis and spinal muscular atrophy, because they can only detect larger chromosomal abnormalities, the company said.

BillionToOne’s March fundraising round was co-led by Hummingbird Ventures and NeoTribe Ventures, with additional support from Y Combinator, Civilization ventures, Fifty Years, 500 Startups Istanbul and HOF Capital. 

The company is also planning to develop a liquid biopsy diagnostic in the cancer space over the next year, using its cell-free DNA and molecule-counting platform.