Sickle cell disease refers to a group of genetic disorders that affect hemoglobin. These disorders can be life threatening, but there are ways to manage the symptoms.
Red blood cells contain hemoglobin, which is a molecule that delivers oxygen to the body’s tissues. In sickle cell disease, a problem with hemoglobin means that the red blood cells are C shaped (like a sickle) and sticky.
As a result, they can stick in the cardiovascular system. They are also unable to deliver oxygen effectively. This can affect the body in various ways.
Currently, the only cure for sickle cell disease is a stem cell transplant, but organizations such as the Sickle Cell Disease Association of America are working to raise awareness and encourage funding for more research into this condition.
According to Genetics Home Reference, sickle cell disease disproportionately affects “people whose ancestors come from Africa; Mediterranean countries such as Greece, Turkey, and Italy; the Arabian Peninsula; India, and Spanish-speaking regions in South America, Central America, and parts of the Caribbean.”
This article will look at why sickle cell disease occurs, how it affects the body, and some treatment options.
Sickle cell disease is a genetic condition. A person can only have it if they inherit one or more faulty genes from their biological parents.
If a person has a faulty gene from just one parent, they will have sickle cell trait but not sickle cell disease. If a person inherits a faulty gene from each parent, they will have sickle cell disease.
There are several different types of sickle cell disease. The main ones include:
- HbSS: A person inherits two sickle cell genes, one from each parent. They will have sickle cell anemia, which is the most severe type of sickle cell disease. Doctors call it HbSS.
- HbSC: A person inherits a sickle cell gene from one parent. From the other parent, they inherit a gene that results in another type of abnormal hemoglobin. HbSC is usually less severe than HbSS.
- HbS beta-thalassemia: A person inherits a sickle cell gene from one parent and a gene for beta-thalassemia, another type of anemia, from the other.
- Sickle cell trait: If a person has only one sickle cell gene, they will not have sickle cell disease, but they can pass that gene to their children. A person with one faulty gene has sickle cell trait.
Who does it affect?
Sickle cell disease can affect anyone, but it is more common among Black people. People of Mediterranean, South American, Middle Eastern, and South Asian ancestry also have higher rates of sickle cell disease.
According to the Centers for Disease Control and Prevention (CDC), about 100,000 people in the United States have sickle cell disease. Around 1 in 365 Black Americans are born with the disease, and 1 in 13 are born with the trait. Sickle cell disease affects about 1 in 16,300 Hispanic Americans.
Sickle cell disease appears to be more likely in areas where malaria is common. However, the CDC note that people with sickle cell disease seem to have a lower risk of some severe types of malaria.
If the body’s cells do not receive enough oxygen, many symptoms and complications can arise. These can happen at any age, and they will vary among individuals.
Sickle cells break down more easily than healthy red blood cells. This can result in low levels of red blood cells, known as anemia.
Early symptoms may include:
- jaundice, or a yellowing of the skin and the whites of the eyes
- pain and swelling in the hands and feet
Further symptoms and complications may include:
- episodes of pain
- swelling in the hands and feet
- acute chest syndrome
- vision loss
- enlarged spleen
- leg ulcers
- deep vein thrombosis
- liver, heart, or kidney damage
- malnutrition (in young people)
- infertility (in males)
- priapism, which refers to a prolonged and painful erection
- pulmonary hypertension, which is high blood pressure in the blood vessels that supply the lungs
- heart failure
- bone and joint damage, which occurs due to low blood supply
- a higher risk of infections, which may have severe symptoms
The following list will provide more detail about some of the main symptoms and complications of sickle cell disease:
- Pain: During a pain episode, sickle cells get stuck and prevent blood from flowing to a part of the body. The pain can range from mild to severe, and it can last for any length of time.
- Infections: The CDC warn that people with sickle cell disease may have a higher risk of severe illness with COVID-19, regardless of their age.
- Chest symptoms: The symptoms of acute chest syndrome include chest pain, coughing, fever, and difficulty breathing.
- Enlarged spleen: A person may suddenly experience weakness, pale lips, rapid breathing and heart rate, thirst, and abdominal pain.
If any of these symptoms appear, the person needs emergency medical treatment. They may also need to spend time in the hospital.
Because a person inherits it, sickle cell disease is present before birth. A routine blood test at birth will show whether or not the condition is present.
In severe cases, an infant may have an aplastic crisis, in which the bone marrow stops producing red blood cells, leading to severe anemia. They may also have an enlarged spleen due to trapped red blood cells.
Symptoms include a low appetite and sluggishness.
In the U.S., screening for newborns includes a simple pinprick blood test to assess for sickle cell disease and sickle cell trait. If the tests show that the infant has sickle cell disease, the healthcare team will follow up with the family over time.
Tests are also available before birth, starting from weeks 8–10 of pregnancy.
If a person with a family history of sickle cell disease plans to have children, they may wish to meet with a genetic counselor and undergo genetic testing to find out if their children are likely to have the condition.
Treatment will involve a combination of approaches, and the options will depend on the person’s specific needs.
Also, when a person with sickle cell disease experiences pain, a doctor may not treat it as promptly as they do in people who have pain with other conditions. Also, they may not prescribe appropriate dosages of pain medication.
The sections below will discuss the various treatment options for sickle cell disease in more detail.
The following drugs may help reduce the risk of complications:
- Hydroxyurea (Hydrea): This helps ensure the supply of oxygen to the body. It is not safe to use during pregnancy. Research has not proven the benefits of this medication in children younger than 9 months of age.
- L-glutamine oral powder (Endari): This helps reduce the number of sickle cells. It is suitable from the age of 5 years.
- Voxelotor (Oxbryta): This helps boost levels of healthy hemoglobin. It is suitable from the age of 12 years.
- Crizanlizumab-tmca: This can help reduce pain by preventing blood cells from sticking to blood vessels. It is suitable from the age of 16 years.
The CDC advise adults and children to take precautions to reduce the risk of infections. These include:
- practicing regular hand-washing
- following food safety guidelines
- staying away from reptiles, such as turtles, as they may carry Salmonella
- receiving vaccinations for flu, pneumococcal disease, and meningococcal disease
Blood transfusions and stem cell transplants
People with severe symptoms may need a blood transfusion or a stem cell transplant.
Blood transfusions may be necessary if a person has severe anemia, an enlarged spleen, infections, or other complications.
A stem cell transplant using cells from a matched, healthy donor can cure sickle cell disease, but it can be risky. Also, the stem cells must be closely matched.
People with sickle cell disease or sickle cell trait cannot give blood, but healthcare professionals encourage anyone who can donate to do so. This may help a person with these conditions.
Many people have a healthy pregnancy with sickle cell disease. However, there may be a higher chance of:
- experiencing pain and other symptoms
- experiencing preterm birth
- having a baby with a low weight
Receiving appropriate medical care can help reduce these risks.
People with sickle cell disease or sickle cell trait may wish to speak to a genetic counselor if they plan to have children.
Many people with sickle cell disease can live a full and active life, especially if they take action to reduce the effects of the condition.
Lifestyle measures that may help include:
- finding a suitable healthcare team
- following the recommended treatment plan, including attending regular health checks
- learning as much as possible about sickle cell disease
- drinking eight to 10 glasses of water per day
- not getting too hot or too cold, as this may trigger a crisis
- engaging in physical activity but also getting enough rest
- following a healthful diet, as this can boost overall well-being
- checking insurance coverage and eligibility for Medicaid assistance
- joining an online forum or patient registry, such as the Sickle Cell Disease Association of America, to access useful resources
- not smoking, as research suggests that this can affect how much oxygen reaches the blood through the lungs
Health insurance will cover the treatment of sickle cell disease. If a person does not have insurance, they can purchase it under the Affordable Care Act or apply for Medicaid.
Sickle cell disease is a potentially life threatening blood disorder.
Scientists are currently looking for a cure that will help all people with sickle cell disease. They hope to establish a next-generation therapy within 5–10 years.
People who are interested in joining a clinical trial can speak to their doctor or join the National Institutes of Health’s Cure Sickle Cell initiative for more information.
The National Heart, Lung, and Blood Institute provide a list of clinical trials that vary by age groups and other factors.