When you find out your child has sickle cell disease, you want to know what that means for their future. What complications are they likely to face? What treatments will they need, and how will that change as they get older? Knowing what type of sickle cell disease they have can help answer some of these questions.
At UVA Health Children’s, our pediatric comprehensive sickle cell clinic sees children with all forms of sickle cell disease. While some only need check-ins, we also organize and manage more advanced treatments.
Typing Your Child’s Sickle Cell Disease
At your first appointment, we’ll confirm your child’s sickle cell diagnosis. We’ll also talk about what type of sickle cell disease your child has. And what that type means for their future symptoms and treatment.
How Is Sickle Cell Disease Inherited?
Hemoglobin is a protein that red blood cells need. Your child has 2 genes responsible for producing hemoglobin. Because they have sickle cell disease, one of those genes is a sickle cell gene (S). What the other gene is determines what type of sickle cell your child has.
If they have a healthy hemoglobin gene in addition to their sickle cell gene, they have sickle cell trait. Sickle cell trait is normally asymptomatic. But it’s important to be proactive and avoid situations, like high elevations or dehydration, that could cause sudden symptoms. It also means that either you or your partner has the sickle cell trait. Genetic testing can help verify.
All other forms of sickle cell are from inheriting one sickle gene and one other abnormal hemoglobin gene.
Types of Sickle Cell
Hemoglobin SS (HbSS)
HbSS is the most common type of sickle cell disease. This means that both parents have passed a sickle cell gene to their child, resulting in HbSS. More than 60% of people with SCD have this type.
Despite being the most common, this is also one of the more severe forms of sickle cell. We’ll make sure you and your child can get the medications you need and help train you to deal with complications that could happen.
Though the severity is scary, this is also the form of sickle cell disease we have the most information on. We can correctly recommend preventative measures. We also have treatments available that can reduce complications.
Hemoglobin Beta Thalassemia (HbSβth)
Thalassemia is a different blood disorder that is similar to sickle cell. When one parent has the gene for sickle cell and the other has the gene for thalassemia, it causes the child to have this form of SCD.
There are two subtypes of HbSβth. If your child has the ‘plus’ form, that means there are still some normal hemoglobin cells. If they have the ‘zero’ form, no normal hemoglobin cells were found.
Hemoglobin Beta Thalassemia Plus (HbSβ+th)
This is the milder of the two subtypes. It’s not uncommon for children to not show any signs until later in childhood. We’ll still want to schedule regular follow-up. Because this is a rarer type, we know less about why it causes symptoms in one child and not another. Until we’re sure how it affects your child, monitoring is our safest option.
Hemoglobin Beta Thalassemia Zero (HbS β0 th)
This form of sickle cell acts the same as if your child had two sickle cell genes. That means they’re still at risk for severe symptoms. It also means we’ll still suggest the same medications for management as we would with the SS form of sickle cell.
Sickle Cell C (HbSC)
This type is caused by inheriting one sickle cell gene and one hemoglobin gene that is type C. This is usually a milder form of sickle cell disease. Your child may still have more problems with pain, and you’ll need to be aware of complications. But often these children do not need long-term medical management.
Sickle Cell S/O (HbSO)
Sickle Cell SO, sometimes called S/O Arab is a much rarer form of the disease, and we know less about it. So far, in all observed patients, there have been complications due to their red blood cells. We’ll talk with you about management strategies and ensure we’re prepared for complications.
Sickle Cell SE (HbSE)
This form of sickle cell disease is also very mild. Sometimes people don’t experience symptoms until early adulthood. We’ll still want to take early preventative measures. This is one of the rarest types, so we’ll take a cautious approach. It’s estimated that around 30% of people with this form of sickle cell disease still have at least one documented pain crisis.
Which Type Is Sickle Cell Anemia?
While all forms of sickle cell disease can cause anemia, only HbSS and HbS beta zero are considered "sickle cell anemia.” These two forms represent most of the cases of sickle cell. They also require the most follow-up care.
But parents of children with these types should know that treatments for these types have never been better. With regular care, your child can still thrive.