Beta-Thalassemia Carrier Screening & NIPT

What is UNITY Fetal Risk Screen(™) for beta-thalassemia?

UNITY Screen (™) starts with carrier screening for several recessive conditions, including beta-thalassemia. If you are not a carrier, your chance of having an affected baby is low. If you are a carrier, the next step is for UNITY Screen (™) to perform single-gene NIPT which can tell you if your baby has a high-chance of having beta-thalassemia. While not diagnostic, UNITY Screen (™) is a great starting place for expecting parents to learn more about their risk of having a baby with beta-thalassemia.

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The American College of Obstetricians and Gynecologists recommends that anyone planning to start a family or those who are already pregnant be offered carrier screening for inherited conditions, including beta-thalassemia.

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What is beta-thalassemia?

Beta-thalassemia is an inherited condition that affects the red blood cells’ ability to carry oxygen through a molecule called hemoglobin. Hemoglobin is made of alpha and beta chains, and genetic changes in the HBB gene reduce the production of beta-chains, leading to unhealthy red blood cells. 

People with beta-thalassemia produce fewer healthy red blood cells, causing symptoms such as anemia, shortness of breath, fatigue, dizziness, and rapid heartbeat. Severe forms can lead to frequent infections, delayed growth and development, and affect organs like the spleen, liver, or heart. Specific HBB genetic changes determines the severity and type of symptoms a person with beta-thalassemia may have:

• Beta-Thalassemia Trait/Minor: People with beta-thalassemia minor are carriers of the condition and may experience mild anemia but typically do not have significant symptoms.
• Beta-Thalassemia Intermedia: Individuals with beta-thalassemia intermedia can have symptoms ranging from moderate to severe anemia, bone abnormalities, and an enlarged spleen. They may need occasional blood transfusions but are not dependent on them.
• Beta-Thalassemia Major: Also known as Cooley’s anemia, beta-thalassemia major causes severe anemia requiring regular blood transfusions. It poses a risk for organ failure and other life-threatening complications.

Importantly, beta-thalassemia trait can combine with other red blood cell conditions, such as sickle cell disease, leading to combined disorders like sickle-beta-thalassemia disease. So it is important to discuss additional carrier screening for beta-hemoglobinopathies with your provider.

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How is beta-thalassemia inherited?

Beta-thalassemia is inherited from parents who are carriers of the condition (thalassemia minor or beta-thalassemia trait). Carriers often do not show symptoms, so carrier screening can be useful for expecting parents. If both parents are carriers, they each have one working and one non-working copy of the HBB gene. If a baby inherits both non-working copies, they will have beta-thalassemia. Inheritance can be complex, as carriers might also pass on other HBB gene changes, leading to related red blood cell disorders. Carrier screening and additional testing can help predict the type and severity of symptoms of an affected person.

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Who should consider beta-thalassemia screening? 

Carrier screening for beta-thalassemia and other beta-hemoglobinopathies is recommended for all pregnant individuals or those considering pregnancy. UNITY Screen (™) is designed to offer a simple streamlined test to determine your carrier status and the risk of having a baby with beta-thalassemia through single-gene NIPT. If your results show a high risk of any of the conditions screened, you can discuss additional testing either before or after your delivery.

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UNITY Screen (™) Carrier Screening & sgNIPT workflow

With UNITY Screen™, carrier screening is performed first to see if you’re a carrier for beta-thalassemia. If you're not a carrier for beta-thalassemia, the chance your baby is affected is extremely low. If you are found to be a carrier, the second step is to assess your baby's risk for beta-thalassemia. All it takes is a blood sample after 10 weeks in pregnancy.

Consult
The UNITY Screen™ NIPT is ordered through your healthcare provider. You can schedule a complimentary genetic counseling session to answer any questions about the test before or after your blood is drawn.

Test: As early as week 9
Your blood sample can be collected in the doctor’s office, at a local lab, or through our mobile services. Your blood sample is shipped to our CAP/CLIA certified laboratory in northern California.

aneuploidy NIPT + fetal antigen results: As early as week 10
Within about one week from lab receipt, your doctor will receive the baby’s risk score for aneuploidies (chromosome conditions) and fetal antigens (if added). You will receive a text or email indicating your results are available on our portal, or your healthcare provider may call you with the results.

carrier status + single-gene NIPT results: As early as week 11
Within about two weeks from lab receipt, your doctor will receive the results of your maternal carrier status testing and single-gene NIPT. If you were found to be a carrier for any of the recessive conditions, single-gene NIPT is automatically run to determine your baby’s risk of being affected. You will receive a text or email indicating your results are available on our portal, or your healthcare provider may call you with the results.

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What do my beta-thalassemia screening results mean?

UNITY Screen (™) can tell you if you are a carrier for beta-thalassemia, or other recessive conditions. If you are a carrier and currently pregnant, UNITY Screen (™) will also perform single-gene NIPT screening to determine the chance of having a baby affected with beta-thalassemia or other common beta-hemoglobinopathies. These results will either show your baby has a low-risk or a high-risk for beta-thalassemia. If your results show a high-risk, your healthcare provider will discuss the recommended confirmatory testing that can be performed before or after delivery. 

UNITY Screen (™) results are not diagnostic, so there is always the option for additional confirmatory testing to be performed. You can discuss your options and recommendations with your provider or one of our Genetic Counselors:

• Before Birth: Testing during pregnancy can be performed by obtaining a sample of placenta (chorionic villus sampling or CVS) or fluid around your baby (amniocentesis) which both contain DNA that is representative of your baby.  A CVS is ideally performed between 10 to 13 weeks in pregnancy while an amniocentesis is typically performed between 15 to 24 weeks in pregnancy.  Both procedures are generally safe, but have a small risk for pregnancy complications, including miscarriage.‍

• After Birth: Testing for your baby can be performed after birth through a blood test.  In addition, all babies born in a hospital in the United States are automatically screened for common beta-hemoglobinopathies, including beta-thalassemia major. The majority of babies with beta-thalassemia major will be diagnosed through this screening process. However, in rare cases, a diagnosis may be missed or incorrectly diagnosed.

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Cord Blood Banking: Hematopoietic stem cells from umbilical cord blood, which can only be collected at the time of delivery, may be used to treat certain genetic conditions. BillionToOne’s cord blood banking program will cover the costs associated with the collection and first year of storage of cord blood for patients with high risk HBB sgNIPT results. Interested patients should schedule an appointment with a BillionToOne genetic counselor to learn more.

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Frequently Asked Questions

Is there a cure for beta-thalassemia? 

For some people with beta-thalassemia receiving a bone marrow or stem cell transplant can be curative. Recently, the FDA approved a form of gene-therapy to alleviate symptoms and improve quality of life for people with beta-thalassemia who need frequent blood transfusions. More advancements in treating and potentially curing beta-hemoglobinopathies are expected in the future. 

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How is beta-thalassemia treated? 

Treatment for beta-thalassemia is usually coordinated by multiple specialists including a hematologist. It often includes blood transfusions, iron chelation therapy, and medications to alleviate symptoms of anemia. 

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What is cord blood banking?

Cord blood banking occurs at the time of delivery and collects and stores hematopoietic stem cells from umbilical cord blood. For expecting parents, banking cord blood can provide a valuable resource for potential future medical treatments for their child or family members. Coordinating logistics prior to delivery ensures that the collection process is smooth and the cord blood is properly preserved for potential use. BillionToOne’s cord blood banking program will cover the costs associated with the collection and first year of storage of cord blood for patients with high risk HBB sgNIPT results. Interested patients should schedule an appointment with a BillionToOne genetic counselor to learn more.

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Treatments & Resources

• Cooley’s Anemia Foundation: https://www.thalassemia.org/ 
• Thalassemia International Foundation: http://thalassaemia.org.cy/‍
• National Organization for Rare Disorders (NORD): https://rarediseases.org/rare-diseases/thalassemia-major/