Sickle cell disease is a group of inherited red blood cell disorders. Healthy red blood cells are round, and they move through small blood vessels to carry oxygen to all parts of the body. In sickle cell disease, the red blood cells become hard and sticky and look like a C-shaped farm tool called a “sickle”. The sickle cells die early, which causes a constant shortage of red blood cells. Also, when they travel through small blood vessels, they get stuck and clog the blood flow. This can cause pain and other serious problems.
Sickle cell disease is a genetic condition that is present at birth. It is inherited when a child receives two sickle cell genes – one from each parent.
People who inherit one sickle cell gene and one normal gene have the sickle cell “trait”. People with sickle cell trait usually do not have any of the symptoms of the disease, but they can pass it on to their children.
It is possible for a person with sickle cell trait to experience complications of sickle cell disease, such as splenic sequestration, “pain crisis”, and, rarely, sudden death.
This can happen under extreme conditions of:
- High altitude (flying, mountain climbing, or cities with a high altitude)
- Increased pressure (scuba diving)
- Low oxygen (mountain climbing or exercising extremely hard, such as in military boot camp or when training for an athletic competition)
- Dehydration (too little water in the body)
Sickle cell disease is diagnosed with a simple blood test. It is most often found at birth during routine newborn screening tests at the hospital. In addition, sickle cell disease can be diagnosed before birth.Because children with sickle cell disease are at an increased risk of infection and other health problems, early diagnosis and treatment are important. All 50 states in the United States have newborn screening programs for sickle cell disease.
People with sickle cell disease start to have symptoms during the first year of life, usually around 5 months of age. Symptoms and complications of sickle cell disease are different for each person and can range from mild to severe.
- Hand-foot syndromeThis is usually the first symptom of sickle cell disease. Swelling in the hands and feet, often along with a fever, is caused by the sickle cells getting stuck in the blood vessels and blocking the flow of blood in and out of the hands and feet.
- Pain “episode” or “crisis”This is the most common complication, and the top reason that people with sickle cell disease go to the emergency room or hospital. When sickle cells travel through small blood vessels, they can get stuck and clog the blood flow. This causes pain that can start suddenly, be mild to severe, and can last for any length of time.
- AnemiaThis is a very common complication. With sickle cell disease, the red blood cells die early. This means there are not enough healthy red blood cells to carry oxygen throughout the body.
- InfectionPeople with sickle cell disease, especially infants and children, are more at risk for harmful infections. Pneumonia is a leading cause of death in infants and young children with sickle cell disease.
- Acute chest syndromeThis can be life-threatening and should be treated in a hospital. It is similar to pneumonia and symptoms include chest pain, coughing, difficulty breathing, and fever.
- Splenic sequestrationThis can be life-threatening and should be treated in a hospital. It happens when a large number of sickle cells get trapped in the spleen and cause it to suddenly get large. Symptoms include sudden weakness, pale lips, fast breathing, extreme thirst, abdominal (belly) pain on the left side of body, and fast heart beat.
- Vision lossVision loss, including blindness, can occur when blood vessels in the eye become blocked with sickle cells and the retina (the thin layer of tissue inside the back of the eye) gets damaged.
- Leg ulcersThis usually occurs on the lower part of the leg. They happen more often in males than in females and usually appear from 10 through 50 years of age. The cause of leg ulcers is unclear.
- StrokeA stroke can happen if sickle cells get stuck in a blood vessel and clog blood flow to the brain. About 10% of children with sickle cell disease will have a stroke. Stroke can cause lifelong disabilities and learning problems.
- Other possible complications
- Damage to body organs, tissues, or bones because not enough blood is flowing to the affected area(s).
- Painful erection of the penis, called priapism, that can last less than 2 hours or more than 4 hours. If it lasts more than 4 hours, the person should get urgent medical help. It can lead to impotence.
The only cure for SCD is bone marrow/stem cell transplant.
Bone marrow is a soft, fatty tissue inside the center of the bones where blood cells are made. A bone marrow/stem cell transplant is a procedure that takes healthy cells that form blood from one person – the donor – and puts them into someone whose bone marrow is not working properly.
Bone marrow/stem cell transplants are very risky, and can have serious side effects, including death. For the transplant to work, the bone marrow must be a close match. Usually, the best donor is a brother or sister. Bone marrow/stem cell transplants are used only in cases of severe sickle cell disease for children who have minimal organ damage from the disease.
Sickle cell disease is a global health problem.In the United States with an estimated population of over 270 million, about 1,000 babies are born with sickle cell disease each year and it is estimated that over 70,000 people have sickle cell disease.
Sickle cell disease is most common in people whose ancestors come from Africa, South and Central America, the Caribbean islands, India, Saudi Arabia and Mediterranean countries such as Turkey, Greece and Italy.
1 in 500 African Americans and 1 in 1,000-1,400 Hispanic Americans have sickle cell disease.
Facts about Sickle Cell Disease – Centers for Disease Control and Prevention