Company: BLLN
Filing Date: 2025-10-17
Form Type: S-1/A
Source: 0001193125-25-242632
Chunk: 217

Company: BillionToOne, Inc.
Filing Date: 2025-10-17
Form: S-1/A
Chunk 217
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, G., Feldman, K., Grubman, O., Cole, D., Hussain, F., Ashmead, G., Al-Ibraheemi, Z., & Brustman, L. (2023). Barriers to completion 
 of expanded carrier screening in an inner city population. Genetics in Medicine, 25(7), 100858.                                                                                                                       |

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directly measuring fetal risk through a single maternal blood draw is only possible with the precision and sensitivity provided by our smNGS technology. Within two weeks, the information provided to the clinician and patient includes:

| • |     | Maternal carrier status and any information about the specific variant that may be identified; |

| • |     | A personalized fetal risk score on each condition for which the pregnant mother is a carrier, ranging from <1 in 5,000 
 to 9 in 10, providing clear, actionable information for clinicians and patients; and                                   |

| • |     | Whether the risk is classified as low or high risk. |

SUMMARY OF RESULTS A POSITIVE Carrier B LOW RISK Fetus 9.0% fetal fraction UNITY Fetal Risk Screen: Carrier Screen + cfDNA Fetal Risk Assessment C CARRIER SCREEN D cfDNA FETAL RISK ASSESSMENT (pregnant carriers only) Conditions Screened Patient Carrier Status Risk Before cfDNA Fetal Risk After cfDNA ACOG Guideline Panel Alpha-Thalassemia Negative N/A HBA1 HBA2 Cystic Fibrosis POSITIVE 1 in 96 -1 in 376 <1 in 5000 E LOW RISK Sickle Cell Disease / Beta- Thalassemia / Negative N/A Hemoglobinopathies HBB Spinal Muscular Atrophy SMN1 Negative 2 SMN1 copies, SNP not presentN/A Maternal Carrier Results Fetal Risk via cfDNA >99% of patients will be reassured with a low risk result1 Conditions screened align with ACOG recommendations2 Fetal risk is provided for this pregnancy without male partner For positive carriers, risk can be clarified down to 1 in 10,000 or up to 9 in 10 1. Internal Data on File, 2024 2. American College of Obstetricians and Gynecologists. (2017) Carrier screening in the age of genomic medicine (Committee Opinion No. 690). Obstetrics & Gynecology, 129(3), e35-e40