Conditions S, Beta-Thalassemia

S, beta-thalassemia (Hb S/ßTh) is an inherited condition of the blood. Individuals with Hb S/ßTh produce a lower number of red blood cells than healthy people. In a healthy person, red blood cells are a round, donut shape. In a person affected by Hb S/ßTh, some of the red blood cells are a crescent or sickle shape. These unusually shaped cells do not live as long as normal red blood cells and tend to get stuck in blood vessels where they can block the flow of blood to certain parts of the body. If the condition is left untreated, it can cause a shortage of red blood cells (anemia), organ damage, or even death. However, if Hb S/ßTh is identified and treated early in life, children can often lead healthier lives.

Experiences with Hb S/ßTh vary in terms of the severity of the disease. In the most severe cases, the condition is almost identical to sickle cell anemia. However, some individuals have a milder form of the condition and experience very few symptoms.

Condition Type

Hemoglobin Disorders


Hb S/ßTh is a fairly common blood disorder worldwide; thousands of infants with Hb S/ßTh are born each year. Hb S/ßTh occurs most frequently in people from Mediterranean countries, North Africa, the Middle East, India, Central Asia, and Southeast Asia.

Also known as

  • Hb S/ßTh
  • Sickle beta thalassemia
  • Sickle cell-beta thalassemia
  • Hb S/Beta-thalassemia
  • Beta-thalassemia

Follow-Up Testing

If your baby’s newborn screening result for s, beta-thalassemia (Hb S/ßTh) was out of the normal range, your baby’s doctor or the state screening program will contact you to arrange for your baby to have additional testing. It is important to remember that an out-of-range screening result does not necessarily mean that your child has the condition. An out-of-range result may occur because the initial blood sample was too small or the test was performed too early. However, a few babies do have the condition, so it is very important that you go to your follow-up appointment for a confirmatory test. Because symptoms of Hb S/ßTh can develop shortly after birth, follow-up testing must be conducted as soon as possible to determine whether or not your baby has the condition.

Follow-up testing will involve looking at the red blood cells in a sample of your baby’s blood. If your baby has Hb S/ßTh, they may have a reduced number of red blood cells or abnormally shaped red blood cells. Clinical genetic testing for Hb S/ßTh may be necessary to confirm the diagnosis.

Your baby’s doctor may ask you if your baby is showing any of the signs of Hb S/ßTh (see Early Signs below). If your baby has certain signs, your baby’s doctor may need to treat them immediately.

About S, Beta-Thalassemia

Early Signs

Signs of s, beta-thalassemia (Hb S/ßTh) usually begin a couple of months after birth. In some cases, signs may not appear until childhood.

Depending on the severity of the condition, early signs of Hb S/ßTh can include:

  • Sleeping longer or more often
  • Tiredness
  • Difficulty breathing
  • Swelling in the hands or feet
  • Cold hands or feet
  • Pale skin

These signs can occur if your baby has a low number of red blood cells or if the crescent (sickle) shaped red blood cells stick together and block a blood vessel.

If your baby shows any of these signs, be sure to contact your baby’s doctor immediately.

The severity of Hb S/ßTh varies from person to person. In the most severe cases, you may see signs similar to sickle cell anemia. However, some children have a mild form of the condition with very few signs.



Dehydration occurs when an individual does not have enough fluid in their body. Babies with s, beta-thalassemia (Hb S/ßTh) need to get plenty of fluids because dehydration can increase the pain associated with Hb S/ßTh.


Children with Hb S/ßTh may need pain medication. Pain associated with Hb S/ßTh can usually be managed through over-the-counter painkillers like Tylenol. If it continues or becomes severe, your baby’s doctor may prescribe stronger medicines.

If your baby has Hb S/ßTh, they may develop repeated infections, especially during childhood. Your baby’s doctor may prescribe a daily dose of antibiotics to help prevent these infections.

Your baby’s doctor may also prescribe Hydroxyurea if your baby’s Hb S/ßTh is severe. This medication prevents anemia (low levels of red blood cells) by keeping the red blood cells from becoming sickle or crescent-shaped.

Blood Transfusions

Some children with Hb S/ßTh may need a blood transfusion because they do not have enough healthy red blood cells. In this procedure, blood from a healthy individual is given to someone with s, beta-thalassemia.

Expected Outcomes

Treatments can help relieve some of the signs, symptoms, and complications of beta-thalassemia (Hb S/ßTh). Children who receive early and on-going treatment can live healthy lives. With treatment, Hb S/ßTh usually does not shorten life expectancy.

Even with proper treatment, your child may still experience some signs and symptoms such as pain, anemia, and yellowish skin (jaundice). The more carefully you follow your child’s treatment plan, the healthier they can be.

It is important to screen for and treat s, beta-thalassemia because, if untreated, babies with a severe form of the condition can die within their first year of life.


Every cell of the human body needs oxygen. One responsibility of our blood is to bring the oxygen we breathe from our lungs to the different parts of our body. Round or donut-shaped red blood cells carry the oxygen in the blood and can move easily through our blood vessels.

Babies with s, beta-thalassemia (Hb S/ßTh) do not make enough healthy red blood cells. If you baby has Hb S/ßTh, their body makes some red blood cells that are a crescent or sickle shape rather than a round or donut shape. These unusually shaped cells do not live as long as normal red blood cells. This can lead to anemia, a low number of red blood cells.

The sickle or crescent shaped cells also tend to get stuck in blood vessels. When this happens, some parts of the body may not get enough blood. If red blood cells are not able move through the blood vessels, the body cannot get enough oxygen. This can cause many of the signs mentioned in Early Signs.

Hb S/ßTh is an autosomal recessive genetic condition. Hb S/ßTh occurs when a child inherits two non-working genes, one from each parent: one gene with the S trait (sickle cell anemia trait) and one gene with the Beta-thalassemia trait. Both sickle cell anemia and Beta-thalassemia are genetic conditions that affect the quality of the red blood cells.

The parents of a child with Hb S/ßTh each carry a single copy of one of these non-working genes, but they typically do not show signs and symptoms of the condition. While having a child with Hb S/ßTh is rare, when both parents are carriers, they can have more than one child with the condition. Learn more about autosomal recessive inheritance.

Support for S, Beta-Thalassemia

Support Services

Support groups can help connect families who have a child or other family member affected with s, beta-thalassemia with a supportive community of people who have experience and expertise in living with the condition. These organizations offer resources for families, affected individuals, health care providers, and advocates.

Accessing Care

Work with your baby’s doctor to determine the next steps for your baby’s care. Your baby’s doctor may help you coordinate care with a doctor who specializes in blood conditions (hemotology) or other medical resources in your community. A team of specialists can work with your child and family to create an individualized treatment plan.

Because s, beta-thalassemia (Hb S/ßTh) is a genetic condition, you may want to talk with a genetics specialist. A genetic counselor or geneticist can help you understand the causes of the condition, discuss genetic testing for Hb S/ßTh, and understand what this diagnosis means for other family members and future pregnancies. Speak with your baby’s doctor about getting a referral. The Clinic Services Search Engine offered by the American College of Medical Genetics and Genomics (ACMG) and the Find a Genetic Counselor tool on the National Society of Genetic Counselors (NSGC) website are two good resources for you or your baby's health care provider to use to identify local specialists.

Families' Experiences

At this time we have not located a family story for this particular condition. If your family is affected by S, Beta-thalassemia and you would like to share your story, please contact us so other families may benefit from your experience.

References & Sources

Visit Medline Plus Genetics for more condition information

Read this report from the National Institutes of Health to learn about managing sickle cell disease

Visit Cooley's Anemia Foundation for more condition information

Visit the Screening, Technology And Research in Genetics (STAR-G) Project for more information on sickle cell disease

Visit Medscape for information on treatment and management of beta thalassemia

Visit MedlinePlus for more information on thalassemia

ACT Sheets

Healthcare professionals can learn more about confirmatory testing by reading the American College of Medical Genetics and Genomics' Algorithm for Diagnosis and ACT Sheet, a guide for follow-up after newborn screening. You can visit this page of the ACMG website here.

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