How do abnormal hemoglobins arise

Causes - Sickle Cell Disease. Hemoglobin S gene Sickle cell disease is an inherited disease caused by defects, called mutations , in the beta globin gene that helps make hemoglobin. Normal red cells and sickle red cells. Figure A shows normal red blood cells flowing freely in a blood vessel. The inset image shows a cross-section of a normal red blood cell with normal hemoglobin. Figure B shows abnormal, sickled red blood cells blocking blood flow in a blood vessel. The inset image shows a cross-section of a sickle cell with abnormal sickle hemoglobin forming abnormal stiff rods.

How is the hemoglobin S gene inherited? Inheritance pattern for sickle cell disease. The image shows how hemoglobin S genes are inherited. A person inherits two hemoglobin genes—one from each parent. A normal hemoglobin A gene will make normal hemoglobin.

A hemoglobin S gene will make abnormal hemoglobin. In this case, the child does not have sickle cell trait or disease. This child has sickle cell trait. This child has sickle cell disease. Risk Factors - Sickle Cell Disease. About 1 in 13 Black or African American babies is born with sickle cell trait.

About 1 in every Black or African American babies is born with sickle cell disease. About , Americans have sickle cell disease. Screening and Prevention - Sickle Cell Disease. Early signs and symptoms Early symptoms of sickle cell disease may include: A yellowish color of the skin, known as jaundice, or whites of the eyes, known as icterus, that occurs when a large number of red cells undergo hemolysis Fatigue or fussiness from anemia Painful swelling of the hands and feet, known as dactylitis Complications Complications of sickle cell disease include: Acute chest syndrome.

Sickling in blood vessels of the lungs can deprive lungs of oxygen. This can damage lung tissue and cause chest pain, fever, and difficulty breathing. Acute chest syndrome is a medical emergency. Acute pain crisis. Also known as sickle cell or vaso-occlusive crisis, this can happen without warning when sickle cells block blood flow. People describe this pain as sharp, intense, stabbing, or throbbing.

Pain can strike almost anywhere in the body and in more than one spot at a time. Common areas affected by pain include the abdomen, chest, lower back, or arms and legs.

A crisis can be brought on by high altitudes, dehydration, illness, stress, or temperature changes. Often a person does not know what triggers the crisis. Chronic pain. Chronic pain is common, but it can be difficult to describe, but it is usually different from crisis pain or the pain that results from organ damage. Delayed growth and puberty. Children who have sickle cell disease may grow and develop more slowly than their peers because of anemia. They will reach full sexual maturity, but this may be delayed.

Eye problems. Sickle cell disease can injure blood vessels in the eye, most often in the retina. Blood vessels in the retina can overgrow, get blocked, or bleed. This can cause the retina to detach, which means it is lifted or pulled from its normal position.

These problems can lead to vision loss. When red blood cells break down, in a process called hemolysis, they release hemoglobin. Hemoglobin then gets broken down into a substance called bilirubin.

Bilirubin can form stones, called gallstones, that get stuck in the gallbladder. The gallbladder is a small sac-shaped organ beneath the liver that helps with digestion. Heart problems, including coronary heart disease and pulmonary hypertension. Frequent blood transfusions may also cause heart damage from iron overload. The spleen is important for protection against certain kinds of infections. If you have sickle cell disease, a damaged spleen raises the risk for certain infections, including chlamydia, haemophilus influenzae type B, salmonella, and staphylococcus.

Joint problems. Sickling in the hip bones and, less commonly, the shoulder joints, knees, and ankles, can decrease oxygen flow and result in a condition called avascular or aseptic necrosis, which severely damages the joints.

Symptoms include pain and problems with walking and joint movement. Over time, you may need pain medicines, surgery, or joint replacement. Kidney problems. Sickle cell disease may cause the kidneys to have trouble making the urine as concentrated as it should be. This may lead to a need to urinate often and to bedwetting or uncontrolled urination during the night. This often starts in childhood. Leg ulcers.

Sickle cell ulcers are sores that usually start small and then get larger and larger. Some ulcers will heal quickly, but others may not heal and may last for long periods of time. Some ulcers come back after healing.

People who have sickle cell disease usually do not get ulcers until after age Liver problems. Sickle cell intrahepatic cholestasis is an uncommon but severe type of liver damage that happens when sickled red cells block blood vessels in the liver.

This blockage prevents enough oxygen from reaching liver tissue. These episodes are usually sudden and may happen more than once. Children often recover, but some adults may have chronic problems that lead to liver failure. Frequent blood transfusions can lead to liver damage from iron overload. Pregnancy problems. Pregnancy can increase the risk for high blood pressure and blood clots in women who have sickle cell disease.

The condition also increases the risk of miscarriage, premature birth, and low birth weight babies. Learn more about pregnancy and sickle cell disease. Priapism is an unwanted, sometimes prolonged, painful erection. This happens when blood flow out of the erect penis is blocked by sickled cells. Over time, priapism can cause permanent damage to the penis and lead to impotence. Priapism that lasts for more than 4 hours is a medical emergency.

Severe anemia. People who have sickle cell disease usually have mild to moderate anemia. At times, however, they can have severe anemia, which is life-threatening.

Stroke or silent brain injury. Silent brain injury, also called silent stroke, is damage to the brain without showing outward signs of stroke. This injury is common and can be detected on magnetic resonance imaging MRI scans.

Silent brain injury can lead to difficulty in learning, making decisions, or holding down a job. Severe anemia complications People who have sickle cell disease also usually have mild to moderate anemia. Severe anemia in a newborn or child who has sickle cell disease may be a result of: Aplastic crisis. Aplastic crisis is usually caused by a parvovirus B19 infection, also called fifth disease or slapped cheek syndrome.

Parvovirus B19 is a very common infection, but in sickle cell disease, it can cause the bone marrow to stop producing new red cells for a while, leading to severe anemia. Splenic sequestration crisis. Your spleen filters your blood and destroys old blood cells. In people who have sickle cell disease, red blood cells may get trapped in the spleen, making it quickly grow larger than normal. With red blood cells trapped in the spleen, fewer are available to circulate in the blood, and this can lead to severe anemia.

A large spleen may also cause pain in the left side of the belly. Diagnosis - Sickle Cell Disease. Newborn screening When a child has sickle cell disease, early diagnosis is important to better prevent complications. Prenatal screening Doctors can also diagnose sickle cell disease before a baby is born. Treatment - Sickle Cell Disease. Medicines Voxelotor The U. Crizanlizumab-tmca In , the FDA also approved a new medicine to reduce the number of pain crises experienced by adults and children 16 years and older who have sickle cell disease.

Penicillin In children who have sickle cell disease, taking penicillin two times a day has been shown to reduce the chance of having a severe infection caused by the pneumococcus bacteria. Hydroxyurea Hydroxyurea is an oral medicine that has been shown to reduce or prevent several sickle cell disease complications.

Use in adults. It also improved anemia and decreased the need for transfusions and hospital admissions. Use in children. There is no information about how safe or effective hydroxyurea is in children under 9 months of age Pregnant women should not use hydroxyurea. Transfusions Your doctor may recommend transfusion to treat and prevent certain sickle cell disease complications. These transfusions may include: Acute transfusion to treat complications that cause severe anemia.

Doctors may also use transfusions when a patient has an acute stroke, in many cases of acute chest crises, and in multi-organ failure. A patient who has sickle cell disease usually receives blood transfusions before surgery, to prevent complications. Red blood cell transfusions to increase the number of red blood cells and provide normal red blood cells that are more flexible than red blood cells with sickle hemoglobin.

Regular or ongoing blood transfusions for people who have had an acute stroke, to reduce the chances of having another stroke. Doctors also recommend blood transfusions for children who have abnormal transcranial Doppler TCD ultrasound results, because transfusions can reduce the chance of having a first stroke. Some doctors use this approach to treat complications that do not improve with hydroxyurea.

Doctors may also use transfusions in people who have too many side effects from hydroxyurea. Possible complications include alloimmunization , which can make it hard to find a matching unit of blood for a future transfusion; infection; and iron overload. Blood and bone marrow transplant A blood and bone marrow transplant is currently the only cure for sickle cell disease, but it is not for everyone.

Potential genetic therapy treatments for sickle cell disease Researchers at the NHLBI are exploring ways genetic therapies may help develop new treatments or find a cure for sickle cell disease. Living With - Sickle Cell Disease. Receive routine follow-up care See your doctor regularly. Most people who have sickle cell disease should see their doctor every 3 to 12 months, depending on their age. Get regular vaccines, including an influenza or flu shot every year. Your doctor may also recommend a second pneumococcus PPSV23 , in addition to the pneumococcus one PCV13 that all children get as part of their regular immunizations.

This second vaccine is given after 24 months of age and again 5 years later. Adults who have sickle cell disease and have not received any pneumococcal vaccine should get a dose of the PCV13 vaccine. They should later receive the PPSV23 if they have not already received it or if it has been more than 5 years since they did. Follow these guidelines even if you or your child is still taking penicillin.

Learn how to manage pain When an acute crisis is just starting, drink lots of fluids and take a nonsteroidal anti-inflammatory NSAID pain medicine, such as ibuprofen. If you have kidney problems, acetaminophen is often preferred. You may be able to return home once your pain is under better control. You may need to be admitted to the hospital to fully control an acute pain crisis.

Adopt a healthy lifestyle Get regular physical activity. You may tire easily, so be careful to pace yourself and avoid very strenuous activities. Choose heart-healthy foods , including limiting alcohol. Drink extra water to avoid dehydration. Quit smoking. Although these resources focus on heart health, they include basic information about how to quit smoking.

Extreme heat or cold, as well as abrupt changes in temperature, are often triggers. When going swimming, ease into the water rather than jumping right in.

Do not travel in an aircraft cabin that is unpressurized. If you experience priapism prolonged, painful erection , you may be able to relieve your symptoms by doing light exercise, emptying your bladder by urinating, drinking more fluids, and taking medicine recommended by your doctor. If your child attends daycare, preschool, or school, speak to his or her teacher about the disease.

Teachers need to know what to watch for and how to accommodate your child. They should try to feel for the spleen daily and more often when the child is ill. If the spleen feels larger than usual, they should call the care provider. Seek help if you have feelings of depression or anxiety.

Supportive counseling and, sometimes, antidepressant medicines may help. Know when to seek emergency medical care Sickle cell disease can lead to serious and life-threatening health problems. Symptoms of severe anemia, including extreme tiredness fatigue , shortness of breath, dizziness, or irregular heartbeat. Splenic sequestration crisis or an aplastic crisis can cause severe anemia symptoms.

These conditions can be life-threatening. All children and adults who have sickle cell disease and a fever of more than An example of hemoglobin disease is sickle cell anemia.

There are over hemoglobin diseases that have been medically defined by the American College of Medical Genetics.

The Mississippi Hemoglobinopathy Surveillance Registry reports the following diseases:. Sickle cell anemia is one of the most frequently occurring genetic disorders that affect the red blood cells. Sickle cell anemia mostly affects people of African descent but the disease can also affect people of Hispanic, Arabic, Indian or Mediterranean descent.

Sickle cell anemia affects about 90, to , people in the United States, including one in every African-American babies and one in every 36, Hispanic babies. Sickle cell anemia can cause pain, infections and damage to body organs. The pain symptoms of sickle cell anemia appear during a period called a crisis. A crisis can last from a few hours to a week in length. Other symptoms of sickle cell anemia include fever; pain in hands, feet and joints; shortness of breath; pneumonia-like symptoms; dizziness; headache; sores on the legs and an enlarged spleen or liver.

Some adolescents and adults with sickle cell anemia also have chronic pain, which can result from bone and joint damage, ulcers, and other causes. Sickle cell anemia is usually diagnosed in infancy through newborn screening programs. If you or your child develops any of the following problems, see your doctor right away or seek emergency medical care:.

Sickle cell anemia is caused by a mutation in the gene that tells your body to make the iron-rich compound that makes blood red and enables red blood cells to carry oxygen from your lungs throughout your body hemoglobin. In sickle cell anemia, the abnormal hemoglobin causes red blood cells to become rigid, sticky and misshapen. If only one parent passes the sickle cell gene to the child, that child will have the sickle cell trait.

With one normal hemoglobin gene and one defective form of the gene, people with the sickle cell trait make both normal hemoglobin and sickle cell hemoglobin. Their blood might contain some sickle cells, but they generally don't have symptoms. They're carriers of the disease, however, which means they can pass the gene to their children. For a baby to be born with sickle cell anemia, both parents must carry a sickle cell gene. In the United States, sickle cell anemia most commonly affects black people.

If you carry the sickle cell trait, seeing a genetic counselor before trying to conceive can help you understand your risk of having a child with sickle cell anemia. They can also explain possible treatments, preventive measures and reproductive options. Mayo Clinic does not endorse companies or products. Advertising revenue supports our not-for-profit mission. This content does not have an English version. This content does not have an Arabic version.

Overview Sickle cell anemia Open pop-up dialog box Close. Sickle cell anemia Normal red blood cells are rounded and disk-shaped. Request an Appointment at Mayo Clinic.