What is Sickle Cell Disease?

Sickle cell disease is a serious, yet under-discussed and, unfortunately, under-studied condition. It refers to a group of red blood cell disorders that impact the hemoglobin, or the protein that transports needed oxygen through the body. You’ve most likely seen images of what a normal red blood cell looks like, rounded, which makes it traverse seamlessly through the blood vessels, according to the National Heart, Lung and Blood Institute.

It’s when these crucial cells appear distorted in a “sickle” shape — like a small red crescent moon — that they aren’t able to move along with ease, potentially blocking the blood flow. These compromised cells die early, leaving one with a significant shortage of red blood cells. This can be serious, causing something of a domino effect of other health problems. It can result in everything from potential disruptions in vision to infections to even stroke. These serious episodes are known as sickle cell crises, impeding the ability to carry out day-to-day tasks and live pain free. The NIH says that the presence of sickle cell disease, which weakens the immune system, can be a risk factor for other serious conditions. This even includes COVID-19.

The Centers for Disease Control and Prevention (CDC) outlines several types of sickle cell disease:

  • HbSS: Sickle cell anemia, the most severe form, sickle cell genes inherited from both parents.
  • HbSC: A sole sickle cell gene is passed down from one parent, while a gene for abnormal hemoglobin comes from the other. This is less serious form than sickle cell anemia.
  • HbS beta thalassemia: One sickle cell gene comes from one parent while the gene for a different kind of anemia comes from the other.
  • HbSd, HbSE, HbSO: Rare forms of sickle cell disease, with varying levels of severity.
  • HbAS: This refers to people who have sickle cell trait, inheriting one sickle cell gene from one parent and a “normal gene” from the other. These people don’t have signs of the condition, live relatively healthily, but unfortunately can pass the trait to their children. Individuals with this trait experience fatigue more regularly than people with “normal" blood that’s without the presence of sickle cell mutation. This tendency for fatigue can still have negative ramifications in day-to-day life, from work to social interactions.

How is it diagnosed?

It requires a blood test and is usually detected at birth during newborn screenings. A child generally starts showing signs of the disease around 5 months old, with treatment varying depending on a person’s symptoms and severity of disease.

Who gets it?

In the United States alone, the condition impacts around 100,000 people. If you zero in more closely, it is a condition that impacts Black Americans more than any other group. It occurs in 1 out of every 365 Black or African American births and 1 in 13 Black or African American children are born with sickle cell trait, reports the CDC.

The U.S. Department of Health and Human Services writes that sickle cell disease additionally impacts Latinos and people of Mediterranean, Asian, Middle Eastern and Indian descent.

Given how serious it is, does this disease have a cure? Right now, the only known cure is a stem cell or bone marrow transplant, according to the CDC. Stem cell transplants also do not universally benefit everyone. They are most effective with people who already have relatively strong constitutions and immune systems and are very costly. Stem cell disease remains an under-addressed health condition with more work needed here in the U.S. to innovate new and better therapies.

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What is Sickle Cell Disease?
How is it diagnosed?
Who gets it?