Materiały źródłowe

• #1 Sickle Cell Disease (SCD): Types, Symptoms & Causes

  https://my.clevelandclinic.org/health/diseases/12100-sickle-cell-disease

  Sickle cell disease is caused by a genetic mutation in the HBB gene. […] People with SCD received two mutated HBB genes coded for abnormal hemoglobin one from each parent. […] Sickle cell disease is an umbrella term for the many different types of sickle cell disorders. Healthcare providers reserve the term sickle cell anemia for the types of SCD that cause the most severe anemia. […] A bone marrow transplant (stem cell transplant) can cure sickle cell disease. […] A genetic mutation causes abnormal hemoglobin to clump together, causing the red blood cells to turn sickle shaped.

• #1 Sickle cell disease – Wikipedia

  https://en.wikipedia.org/wiki/Sickle_cell_disease

  Sickle cell anemia results in an abnormality in the oxygen-carrying protein haemoglobin found in red blood cells. […] Sickle cell disease occurs when a person inherits two abnormal copies of the -globin gene that makes haemoglobin, one from each parent. […] The mutation which causes sickle cell disease results in an abnormal hemoglobin known as hemoglobin S (HbS), which replaces HbA in adults. […] The gene defect is a single nucleotide mutation of the -globin gene, which results in glutamate being substituted by valine at position 6 of the -globin chain. […] The sickle cell trait provides a carrier with a survival advantage against malaria fatality over people with normal hemoglobin in regions where malaria is endemic. […] Sickle cell disease has an autosomal recessive pattern of inheritance from parents. […] If both parents are carriers for the autosomal recessive gene, there is a 25% chance of their child having and expressing the disorder.

• #1 Sickle Cell Disease – Causes and Risk Factors | NHLBI, NIH

  https://www.nhlbi.nih.gov/health/sickle-cell-disease/causes

  Sickle cell disease is a genetic disorder caused by mutations in hemoglobin genes, leading to a faulty hemoglobin protein, called hemoglobin S. […] These genes make a faulty hemoglobin protein called hemoglobin S. Sickle cell disease can also occur when a child inherits a gene for hemoglobin S (a sickle cell gene) from one parent and a gene for a different type of faulty hemoglobin, such as beta thalassemia or hemoglobin C, from the other parent. […] Each time this couple has a child, the chances of the child having sickle cell disease remain the same. […] The disease is most common in people of African, Middle Eastern, Mediterranean, Central and South American, and South Asian origin or descent. […] Studies show that having the hemoglobin S gene protects against serious malaria. The malaria protection theory explains why the gene mutation leading to hemoglobin S is found more often among people whose ancestry traces to areas where malaria is common. […] Sickled red blood cells are not flexible and can stick to vessel walls, which can block or slow blood flow. […] This can lead to a low number of red blood cells, called anemia.

• #1 Sickle Cell Anemia: Types, Symptoms, and Treatment

  https://www.healthline.com/health/sickle-cell-anemia

  Sickle cell anemia, or sickle cell disease (SCD), is a genetic disease of the red blood cells (RBCs). […] SCD is an autosomal recessive condition. You need two copies of the gene to have the disease. If you have only one copy of the gene, you are said to have sickle cell trait. […] The four main types of sickle cell anemia are caused by different mutations in these genes. […] Hemoglobin SS disease is the most common type of sickle cell disease. It occurs when you inherit copies of the hemoglobin S gene from both parents. […] Hemoglobin SC disease is the second most common type of sickle cell disease. It occurs when you inherit the Hb C gene from one parent and the Hb S gene from the other. […] Hemoglobin SB+ (beta) thalassemia affects beta globin gene production. […] Hemoglobin SB 0 (Beta-zero) thalassemia is the fourth type of sickle cell disease.

• #1 Sickle cell disease: causes, treatments and the patient experience – The Pharmaceutical Journal

  https://pharmaceutical-journal.com/article/ld/sickle-cell-disease-causes-treatments-and-the-patient-experience

  Sickle cell disease (SCD) is a general term for a group of inherited red blood cell disorders. Normal red blood cells have a biconcave disc shape that is flexible and can easily pass through blood vessels. However, those with SCD have abnormalities in their haemoglobin owing to genetic mutations, resulting in their red blood cells becoming ‘sickle’ shaped rather than round. This inhibits the cells’ ability to carry oxygen and can therefore restrict the amount of oxygen received by the limbs and organs. The cells are also rigid and sticky, causing the red blood cells to stick together, reducing their ability to move through the blood vessels easily. This can lead to blockages, which cause the patient significant pain. […] The most common types of SCD are HbSS, HbSC and HbS beta thalassaemia. HbSS SCD occurs when an individual inherits two genes that code for haemoglobin ‘S’, the abnormal form of haemoglobin that causes the sickle shape of the red blood cell. This type is often referred to as sickle cell anaemia and is the most severe form. HbSC SCD occurs when an individual inherits one haemoglobin ‘S’ and one haemoglobin ‘C’ gene. Both cause abnormal red cell shapes, but this is usually a milder form of SCD. HbS beta thalassaemia occurs when an individual inherits one ‘S’ gene and one beta thalassaemia gene; both genes cause abnormal red blood cell shapes.

• #1 ECU Health Comprehensive Sickle Cell Program – About Sickle Cell Disease | ECU Physicians – A Proud Part of ECU Health | ECU

  https://ecuphysicians.ecu.edu/sickle-cell/about/

  SCD 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 have this form of SCD inherit two sickle cell genes (S), one from each parent. This is commonly called sickle cell anemia and is usually the most severe form of the disease. […] People who have this form of SCD inherit a sickle cell gene (S) from one parent and from the other parent a gene for an abnormal hemoglobin called C. […] People who have this form of SCD inherit one sickle cell gene (S) from one parent and one gene for beta thalassemia, another type of anemia, from the other parent. […] People who have these forms of SCD inherit one sickle cell gene (S) and one gene from an abnormal type of hemoglobin (D, E, or O).

• #1

  https://www.nhs.uk/conditions/sickle-cell-disease/

  Sickle cell disease is caused by a gene that affects how red blood cells develop. […] If both parents have the gene, there’s a 1 in 4 chance of each child they have being born with sickle cell disease. […] The child’s parents often will not have sickle cell disease themselves and they’re only carriers of the sickle cell trait.

• #1 Sickle Cell Anemia and Stroke | Texas DSHS

  https://www.dshs.texas.gov/newborn-screening-program/sickle-cell-disease/more-about-sickle-cell/sickle-cell-anemia-stroke

  A stroke is a sudden and severe complication of sickle cell anemia. It affects between 6% to 8% of patients with sickle cell anemia, especially between two and ten years of age. A stroke may occur with a painful episode or an infection, but in most cases there are no related illnesses. […] The sickled cells in a child with sickle cell anemia have a hard time moving through the blood vessels in the brain. If some cells get „stuck” and can’t move, other sickled cells pile up behind and cause a „log jam” that blocks the blood vessels. Oxygen can’t get past the block to other parts of the brain, which causes the stroke.

• #1 What is Sickle Cell Disease (SCD)? – Sickle Cell Disease Association of America Inc.

  https://www.sicklecelldisease.org/sickle-cell-health-and-disease/types/

  If one parent has Sickle Cell Anemia (SS disease) and the other is Normal, all of the children will have sickle cell trait. […] If one parent has Sickle Cell Anemia (SS) and the other has Sickle Cell Trait (AS), there is a 50% chance (or 1 out of 2) of having a baby with either sickle cell disease or sickle cell trait with each pregnancy. […] When both parents have Sickle Cell Trait, they have a 25% chance (1 of 4) of having a baby with sickle cell disease with each pregnancy. […] The majority of individuals with sickle cell disease have hemoglobin S, but some make a different type of abnormal hemoglobin like hemoglobin C, hemoglobin D, or hemoglobin E. Also, some individuals can have sickle cell disease because of co-inheritance of beta thalassemia. It is important to speak to your physician to understand what type you have.

• #1 Sickle Cell Disease | Boston Children’s Hospital

  https://www.childrenshospital.org/conditions/sickle-cell-disease

  Sickle cell disease is an inherited blood disorder. […] The following are the most common ways a child can develop sickle cell disease: If both parents have sickle cell trait, each of their children will have a 25 percent chance of having sickle cell disease. If one parent has sickle cell disease and the other has sickle cell trait, each of their children will have a 50 percent chance of having sickle cell disease and a 50 percent chance of having sickle cell trait. If one parent has sickle cell disease and the other does not, all of their children will have sickle cell trait, but none of them will have sickle cell disease.

• #1 What is Sickle Cell? | Sickle Cell Speaks

  https://www.sicklecellspeaks.com/understanding-sickle-cell/what-is-sickle-cell

  Sickle cell is an inherited condition that is passed down from your parents the same way people get the color of their eyes, skin and hair. […] Sickle cell begins with hemoglobin, the part of the red blood cell that carries oxygen. […] When red blood cells sickle, they cant do their job of carrying oxygen throughout the body as well. […] The process of hemoglobin clumping together to form a long chain inside the red blood cells is called polymerization. This chain of hemoglobin is what causes the red blood cells to change into a sickled shape. […] Anemia, which is having too few red blood cells. […] It is unknown how much each of these components of sickle cell may impact your overall health. […] Sickle cell disease changes over time, impacting your overall health.

• #1 What Can Trigger Sickle Cell Crisis? – BuzzRx

  https://www.buzzrx.com/blog/what-can-trigger-sickle-cell-crisis

  Sickle cell disease is an inherited autosomal recessive disorder. It occurs when a person inherits one copy of a defective gene from each parent. The gene involved in SCD affects hemoglobin formation in red blood cells. […] Sickle cells have a shorter lifespan than healthy red blood cells. These abnormal cells die within 10-20 days instead of the usual 120 days. This results in anemia and causes fatigue because there isn’t enough oxygen delivery by the sickle cell hemoglobin to various tissues in the body. […] In this type of sickle cell crisis, a viral infection temporarily suppresses RBC precursor cells in the marrow, causing worsening anemia. […] In this SCD crisis, a bacterial infection causes the spleen to enlarge rapidly, trapping red blood cells and preventing them from re-entering the circulation, causing worsening anemia. […] This sickle cell crisis is characterized by increased destruction of red blood cells due to infections, toxins, or certain drugs. […] Acute chest syndrome is a life-threatening complication of sickle cell disease that can be triggered by infections, asthma, and pain crises.

• #1 Sickle cell disease is a genetic disorder that causes lifelong suffering – here’s what you need to know

  https://theconversation.com/sickle-cell-disease-is-a-genetic-disorder-that-causes-lifelong-suffering-heres-what-you-need-to-know-243827

  Sickle cell disease is a genetic disorder caused by inherited mutations in a persons DNA that affect the properties of haemoglobin. […] Sickle cell disease changes adult beta-globin. Instead of two alpha and two healthy beta chains, sickle cell disease patients have two alpha and two mutant beta chains. The resulting haemoglobin is called HbS. […] HbS has different characteristics to normal adult haemoglobin, causing severe symptoms. […] The clots change oxygen and acidity locally, causing more sickling. […] Repeated clotting scars and destroys the spleen, increasing the risk of recurrent infections, often by streptococcal bacteria which can cause severe pneumonia and sepsis. […] Haemolysis leads to inflammation and damages blood vessels, further aggravating sickling symptoms.

• #1 Sickle Cell Crisis: Triggers, Prevention, and Management

  https://www.healthline.com/health/sickle-cell-crisis-triggers

  Sickle cell disease (SCD) is a genetic condition that affects the shape and function of your red blood cells (RBCs). […] However, if you have SCD, certain genetic mutations make your RBCs rigid and shaped like the letter C or a sickle. This makes it hard for RBCs to capture and carry enough oxygen. […] Scientists dont completely understand the exact causes of a sickle cell crisis. Most of the time, it happens because of a physical trigger, but it can also occur without a known cause. […] Most commonly, any triggers that cause your blood vessels to constrict can result in a sickle cell crisis. These triggers include: physical or psychological stress, cold weather, pain, alcohol, tobacco products, loss of fluids (dehydration), infection, low blood oxygen (hypoxemia), which can result from very strenuous exercise, high altitude, or certain medical conditions.

• #1 Sickle Cell Crisis: Symptoms, Causes, Treatment, Prevention

  https://www.webmd.com/a-to-z-guides/sickle-cell-crisis

  Typically, you wont know why you had a crisis, and there may be more than one cause. Possible triggers include: […] Being at high altitudes (mountain climbing, for example) […] Changes in temperature, like if you go from a warm house into a cold winter day and you havent bundled up […] Infections […] Not having enough to drink (dehydration) […] Stress.

• #1 Sickle Cell Disease (SCD): Practice Essentials, Background, Genetics

  https://emedicine.medscape.com/article/205926-overview

  The sickling process that prompts a crisis may be precipitated by multiple factors. Local tissue hypoxia, dehydration secondary to a viral illness, or nausea and vomiting, all of which lead to hypertonicity of the plasma, may induce sickling. Any event that can lead to acidosis, such as infection or extreme dehydration, can cause sickling. More benign factors and environmental changes, such as fatigue, exposure to cold, and psychosocial stress, can elicit the sickling process. A specific cause is often not identified. […] Vaso-occlusive crises are often precipitated by the following: Cold weather (due to vasospasm), Hypoxia (eg, flying in unpressurized aircraft), Infection, Dehydration (especially from exertion or during warm weather), Acidosis, Alcohol intoxication, Emotional stress, Pregnancy. […] Aplastic crises are often preceded by the following: Infection with parvovirus B19, Folic acid deficiency, Ingestion of bone marrow toxins (eg, phenylbutazone). […] Acute chest syndrome has been linked to the following: Fat embolism, Infections, Pain episodes, Asthma.

• #1 Overview of the pulmonary complications of sickle cell disease – UpToDate

  https://www.uptodate.com/contents/overview-of-the-pulmonary-complications-of-sickle-cell-disease/print

  Sickle cell anemia is caused by homozygous sickle mutation (Hb SS). The sickle mutation causes substitution of a valine for glutamic acid as the seventh amino acid of the beta globin chain. […] Etiologies include pulmonary vaso-occlusion and ischemia, pneumonia, fat embolization, and thrombosis (either intravascular or thromboembolic). Infection remains a significant cause of ACS, especially in children, and infectious etiologies are essential to investigate and treat.

• #1 Sickle Cell Disease – Hematology and Oncology – Merck Manual Professional Edition

  https://www.merckmanuals.com/professional/hematology-and-oncology/anemias-caused-by-hemolysis/sickle-cell-disease

  Sickle cell anemia is caused by homozygous inheritance of genes for hemoglobin (Hb) S or Hb S beta 0 thalassemia. […] Hemoglobinopathies are genetic disorders affecting the hemoglobin molecule. […] In hemoglobin S, valine is substituted for glutamic acid in the sixth amino acid of the beta chain. […] Patients who are homozygous for HbS (approximately 0.3% of people with African ancestry in the United States) have sickle cell anemia; patients who are heterozygous, called sickle cell trait (about 8% of people with African ancestry in the United States), are not anemic but have a risk of other complications. […] The homozygous state is differentiated from other hemoglobinopathies by electrophoresis showing only Hb S with a variable amount of Hb F. […] Chronic compensatory bone marrow hyperactivity and ischemic damage deform the bones. […] Patients have various acute exacerbations including painful crisis, sequestration crisis, aplastic crisis, and acute chest syndrome. […] Long-term consequences include pulmonary hypertension, chronic kidney disease, stroke, aseptic necrosis, and increased risk of infection.

• #1 Sickle Cell Disease (SCD): Practice Essentials, Background, Genetics

  https://emedicine.medscape.com/article/205926-overview

  SCD originated in West Africa, where it has the highest prevalence. It is also present to a lesser extent in India and the Mediterranean region. DNA polymorphism of the beta S gene suggests that it arose from five separate mutations: four in Africa and one in India and the Middle East. The most common of these is an allele found in Benin in West Africa. The other haplotypes are found in Senegal and Bantu, Africa, as well as in India and the Middle East. […] The HbS gene, when present in homozygous form, is an undesirable mutation, so a selective advantage in the heterozygous form must account for its high prevalence and persistence. Malaria is possibly the selecting agent because a concordance exists between the prevalence of malaria and Hb S. Sickling might protect a person from malaria by either (1) accelerating sickling so that parasitized cells are removed or (2) making it more difficult for the parasite to metabolize or to enter the sickled cell. While children with sickle cell trait Hb SA seem to have a milder form of falciparum malaria, those with homozygous Hb S have a severe form that is associated with a very high mortality rate.

• #1 Sickle Cell Disease (Sickle Cell Anemia) – Causes & Types

  https://www.webmd.com/a-to-z-guides/what-is-sickle-cell-disease

  Sickle cell disease is caused by a problem in the hemoglobin-beta gene found on chromosome 11. The defect forms abnormal hemoglobin. […] Both your parents need to pass the abnormal hemoglobin gene on to you for you to develop the disease. If both your parents carry the defective gene, you have a 1 in 4 chance of inheriting the disease and becoming sick with it. […] Sickle cell disease occurs in around 1 of every 365 births of Black children, and about 100,000 Americans live with the disease. The National Heart, Lung, and Blood Institute estimates that 9 in 10 people in the U.S. with sickle cell disease have African ancestry or identify as Black. It’s believed that people with ancestry in tropical regions such as Africa carry this genetic mutation that evolved thousands of years ago as a protection against malaria. […] Sickle cell disease is caused by a genetic mutation in the hemoglobin within red blood cells. This abnormal hemoglobin sticks together, changing the shape of a person’s red blood cells. These misshapen cells can disrupt blood flow, leading to pain, anemia, infection, and other complications.

• #1 Sickle cell anemia Information | Mount Sinai – New York

  https://www.mountsinai.org/health-library/diseases-conditions/sickle-cell-anemia

  Sickle cell disease is caused by an abnormal type of hemoglobin called hemoglobin S. Hemoglobin is a protein inside red blood cells that carries oxygen. […] Sickle cell disease is inherited from both parents. If you get the sickle cell gene from only one parent, you will have sickle cell trait. People with sickle cell trait do not have the symptoms of sickle cell disease. […] Sickle cell disease is much more common in people of African and Mediterranean descent. It is also seen in people from South and Central America, the Caribbean, and the Middle East. […] Causes of death include organ failure and infection.

• #1 Sickle Cell Disease – TIF

  https://thalassaemia.org.cy/haemoglobin-disorders/sickle-cell-disease/

  Sickle Cell Disease (SCD) is caused by a haemoglobin defect, a structural variant known as Haemoglobin S, which replaces both -globin subunits in haemoglobin. […] The sickle cell condition can be caused when a person inherits the sickle cell gene from both parents (HbS/HbS) or if co-inherited with HbC or HbD or OArab (other variants) and with -thalassaemia. […] It is believed that the sickle cell abnormal haemoglobin originated in Africa, where it is most commonly encountered, while India is considered as an additional place of origin. […] About 7% of the global population carries an abnormal haemoglobin gene, with more than 500,000 affected children born annually. […] Newborn or neonatal screening can identify both carriers of SCD, but also affected patients. […] A whole variety of complications can occur in this condition and often these occur suddenly following a painful crisis. […] Treatment is usually aimed at avoiding crises, relieving symptoms and preventing complications.

• #1 Sickle cell disease: MedlinePlus GeneticsLock

  https://medlineplus.gov/genetics/condition/sickle-cell-disease/

  Sickle cell disease is a group of disorders that affects hemoglobin, the molecule in red blood cells that delivers oxygen to cells throughout the body. […] Variants (also called mutations) in the HBB gene cause sickle cell disease. The HBB gene provides instructions for making one part of hemoglobin. […] In people with sickle cell disease, at least one of the beta-globin subunits in hemoglobin is replaced with hemoglobin S. In sickle cell anemia (also called homozygous sickle cell disease or HbSS disease), which is the most common form of sickle cell disease, hemoglobin S replaces both beta-globin subunits. […] This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell must have a variant to cause the disorder.

• #1 Sickle Cell Anemia – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK482164/

  Sickle cell anemia is an inherited disorder of the globin chains that causes hemolysis and chronic organ damage. […] The sickle cell mutation occurs when negatively charged glutamate is replaced by a neutral valine at the sixth position of the beta-globin chain. The mutation is transmitted via Mendelian genetics and is inherited in an autosomal codominant fashion. […] A homozygous mutation leads to the severest form of SCD, ie, SCA- also called HBSS disease. […] The coinheritance of beta-naught thalassemia and sickle cell mutation leads to HBS-Beta-0 disease, which phenotypically behaves like HBSS disease. […] Several other compound heterozygotes exist where a single copy of the mutated beta-globin gene is coinherited with a single copy of another mutated gene. […] The second most common variant of SCD is the HbSC disease, where the sickle cell gene is coinherited with a single copy of the mutated hemoglobin C gene. HbC is formed when lysine replaces glutamine at the sixth position on the beta-globin chain.

• #1 What Causes Sickle Cell Disease?Share to Facebookprint pageBookmark for latercaret iconFollow us on facebookFollow us on instagramFollow us on facebookFollow us on linkedincaret icon

  https://sickle-cell.com/causes

  Sickle cell disease (SCD) is a genetic disorder caused by a mutation in the HBB gene. This gene provides instructions for the body to produce a part of hemoglobin. Hemoglobin is a protein that carries oxygen throughout the body. […] A mutation in the HBB gene causes hemoglobin to clump together and change the shape of red blood cells. This can lead to anemia and blocked blood flow for people with SCD. […] SCD can only be inherited if each parent passes down a mutated HBB gene. This means it is a recessive trait. It also means a person cannot get SCD later in life. […] Mutation of a single nucleotide on the HBB gene causes a single amino acid mutation on the beta-globin protein. This is an example of a “missense mutation.” […] Sickle hemoglobin, also called hemoglobin S (HbS), is the most common form of abnormal hemoglobin. It has 2 normal alpha globins but contains 2 sickle beta globins.

• #1 Sickle cell disease: Causes, types, symptoms, and more

  https://www.medicalnewstoday.com/articles/315801

  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 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. […] Sickle cell disease can affect anyone, but it is more common among Black people. […] Sickle cell disease appears to be more likely in areas where malaria is common.

• #1 Sickle Cell Anemia – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK482164/

  The sickle cell mutation occurs when negatively charged glutamate is replaced by a neutral valine at the sixth position of the beta-globin chain. […] The mutation is transmitted via Mendelian genetics and is inherited in an autosomal codominant fashion. […] A homozygous mutation leads to the severest form of SCD, ie, SCA- also called HBSS disease. […] The coinheritance of beta-naught thalassemia and sickle cell mutation leads to HBS-Beta-0 disease, which phenotypically behaves like HBSS disease. […] Several other compound heterozygotes exist where a single copy of the mutated beta-globin gene is coinherited with a single copy of another mutated gene. […] The second most common variant of SCD is the HbSC disease, where the sickle cell gene is coinherited with a single copy of the mutated hemoglobin C gene. HbC is formed when lysine replaces glutamine at the sixth position on the beta-globin chain.

• #1 Sickle cell anemia – Symptoms & causes – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/sickle-cell-anemia/symptoms-causes/syc-20355876

  Sickle cell anemia is caused by a change in the gene that tells the body to make hemoglobin. Hemoglobin is the iron-rich compound in red blood cells that allows these cells to carry oxygen from the lungs to the rest of the body. The hemoglobin associated with sickle cell anemia causes red blood cells to become rigid, sticky and misshapen. […] For a child to have sickle cell anemia, both parents must carry one copy of the sickle cell gene and pass both copies to the child. […] If only one parent passes the sickle cell gene to the child, that child will have the sickle cell trait. With one typical hemoglobin gene and one sickle cell gene, people with the sickle cell trait make both typical hemoglobin and sickle cell hemoglobin.

• #1 Sickle Cell Disease (Anemia): Symptoms, Treatment, and Life Expectancy

  https://www.medicinenet.com/sickle_cell/article.htm

  Interestingly, the sickle cell gene somewhat protects against malaria infection. This makes those with sickle cell trait (gene carriers) at least partially resistant to malaria. Furthermore, the geographic distribution of the sickle cell gene is similar to that of malaria infection. Sickle cell anemia is a lethal condition that threatens life. However, there may be a selective advantage to being a sickle cell carrier (trait) if the person resides in an area of the world where malaria is very common. The advantage a person with sickle cell trait has over a non-carrier of the gene may explain why sickle cell anemia did not disappear from the world even though it is lethal. […] Sickle cell anemia is an inherited illness. Both parents must be carriers of the sickle cell gene for a child to be affected with sickle cell anemia. If each parent is a carrier, any child has a 1 in 2 chance (50%) of also being a carrier and a one in four (25%) chance of inheriting both genes from the parents and being affected with sickle cell anemia.

• #2 Sickle Cell Anemia: Symptoms, Causes & Treatment

  https://my.clevelandclinic.org/health/diseases/4579-sickle-cell-anemia

  Sickle cell anemia is caused by genetic changes (mutations) that lead to abnormal red blood cells and anemia. […] Sickle cell anemia happens when you inherit genetic mutations (changes) that affect the HBB gene. This gene gives instructions on how to make beta-globin, which is part of your hemoglobin protein. Hemoglobin helps your red blood cells to carry oxygen throughout your body. […] You may be born with sickle cell anemia if you inherit one type of changed gene from both of your biological parents. Other forms of sickle cell disease occur when you inherit two different changed genes, one from each biological parent. Healthcare providers may call this a variant genetic mutation (change).

• #2 Sickle Cell Disease (SCD): Practice Essentials, Background, Genetics

  https://emedicine.medscape.com/article/205926-overview

  SCD originated in West Africa, where it has the highest prevalence. It is also present to a lesser extent in India and the Mediterranean region. DNA polymorphism of the beta S gene suggests that it arose from five separate mutations: four in Africa and one in India and the Middle East. The most common of these is an allele found in Benin in West Africa. The other haplotypes are found in Senegal and Bantu, Africa, as well as in India and the Middle East. […] The HbS gene, when present in homozygous form, is an undesirable mutation, so a selective advantage in the heterozygous form must account for its high prevalence and persistence. Malaria is possibly the selecting agent because a concordance exists between the prevalence of malaria and Hb S. Sickling might protect a person from malaria by either (1) accelerating sickling so that parasitized cells are removed or (2) making it more difficult for the parasite to metabolize or to enter the sickled cell. While children with sickle cell trait Hb SA seem to have a milder form of falciparum malaria, those with homozygous Hb S have a severe form that is associated with a very high mortality rate.

• #2 Azthena logo with the word Azthena

  https://www.news-medical.net/health/Sickle-Cell-Disease-Pathophysiology.aspx

  Sickle cell disease is an inherited genetic condition that involves defects in the shape and function of hemoglobin in the blood. This increases the likelihood of blockages in the blood vessels and disrupted blood flow, which can result in serious complications. […] The specific genetic mutation that results in sickle hemoglobin involves a substitution of thymine for adenine (from GAG to GTG) on the sixth codon of the genetic sequence. This leads to the coding of valine rather than glutamate on the sixth position of the hemoglobin beta chain. […] Sickle cell disease is an inherited condition that follows an autosomal recessive pattern. This means that males and females are affected equally and both parents must carry the genetic mutation, even if they are asymptomatic, for the child to be affected.

• #2 ECU Health Comprehensive Sickle Cell Program – About Sickle Cell Disease | ECU Physicians – A Proud Part of ECU Health | ECU

  https://ecuphysicians.ecu.edu/sickle-cell/about/

  SCD 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 have this form of SCD inherit two sickle cell genes (S), one from each parent. This is commonly called sickle cell anemia and is usually the most severe form of the disease. […] People who have this form of SCD inherit a sickle cell gene (S) from one parent and from the other parent a gene for an abnormal hemoglobin called C. […] People who have this form of SCD inherit one sickle cell gene (S) from one parent and one gene for beta thalassemia, another type of anemia, from the other parent. […] People who have these forms of SCD inherit one sickle cell gene (S) and one gene from an abnormal type of hemoglobin (D, E, or O).

• #2 Sickle Cell Anemia – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK482164/

  Sickle cell anemia is an inherited disorder of the globin chains that causes hemolysis and chronic organ damage. […] The sickle cell mutation occurs when negatively charged glutamate is replaced by a neutral valine at the sixth position of the beta-globin chain. The mutation is transmitted via Mendelian genetics and is inherited in an autosomal codominant fashion. […] A homozygous mutation leads to the severest form of SCD, ie, SCA- also called HBSS disease. […] The coinheritance of beta-naught thalassemia and sickle cell mutation leads to HBS-Beta-0 disease, which phenotypically behaves like HBSS disease. […] Several other compound heterozygotes exist where a single copy of the mutated beta-globin gene is coinherited with a single copy of another mutated gene. […] The second most common variant of SCD is the HbSC disease, where the sickle cell gene is coinherited with a single copy of the mutated hemoglobin C gene. HbC is formed when lysine replaces glutamine at the sixth position on the beta-globin chain.

• #2 Sickle cell disease

  https://womenshealth.gov/a-z-topics/sickle-cell-disease

  Hemoglobin (Hb) S beta thalassemia. People with HbS beta thalassemia inherit one hemoglobin S gene and one gene for beta thalassemia, another type of anemia. Anemia is when you have low numbers of red blood cells. There are two types of beta thalassemia, called zero and plus, written as „0” or „+.” People with HbS beta 0 thalassemia usually have a more severe or serious type of sickle cell disease. People with HbS beta + thalassemia usually have a less severe type of sickle cell disease. […] People who have sickle cell trait have one gene that causes sickle cell disease and one normal gene. Because they have only one sickle cell gene, they do not have the disease. Most people who have sickle cell trait, or just one sickle cell gene, do not have any symptoms of the disease and can live a normal, active life.

• #2 What is Sickle Cell Disease (SCD)? – Sickle Cell Disease Association of America Inc.

  https://www.sicklecelldisease.org/sickle-cell-health-and-disease/types/

  If one parent has Sickle Cell Anemia (SS disease) and the other is Normal, all of the children will have sickle cell trait. […] If one parent has Sickle Cell Anemia (SS) and the other has Sickle Cell Trait (AS), there is a 50% chance (or 1 out of 2) of having a baby with either sickle cell disease or sickle cell trait with each pregnancy. […] When both parents have Sickle Cell Trait, they have a 25% chance (1 of 4) of having a baby with sickle cell disease with each pregnancy. […] The majority of individuals with sickle cell disease have hemoglobin S, but some make a different type of abnormal hemoglobin like hemoglobin C, hemoglobin D, or hemoglobin E. Also, some individuals can have sickle cell disease because of co-inheritance of beta thalassemia. It is important to speak to your physician to understand what type you have.

• #2 Sickle Cell Disease | Sickle Cell Anemia | MedlinePlus

  https://medlineplus.gov/sicklecelldisease.html

  Sickle cell disease (SCD) is caused by a variant (change) in a gene that has instructions for your body to make one part of the hemoglobin. This changed gene is sometimes called a sickle cell gene. People with SCD are born with two sickle cell genes, one from each parent. […] If you are born with one sickle cell gene, it’s called sickle cell trait. People with sickle cell trait are generally healthy, but they can pass the defective gene on to their children.

• #2 What Causes Sickle Cell Anemia? – NowPatient

  https://nowpatient.com/blog/what-causes-sickle-cell-anemia

  If both parents are carriers of the sickle cell gene, each of their children has a 25% chance of inheriting the disease, a 50% chance of inheriting the sickle cell trait, and a 25% chance of inheriting two normal hemoglobin genes. […] On the other hand, if one parent has sickle cell disease and the other is a carrier, each of their children has a 50% chance of inheriting the disease and a 50% chance of inheriting the sickle cell trait. […] Certain ethnic and racial groups are at a higher risk of developing sickle cell anemia due to their genetic makeup. […] In addition to those of African, Mediterranean, and Middle Eastern descent, the disease can also affect those with ancestry from South America, the Caribbean, and parts of Asia.

• #2 Sickle Cell Disease | Boston Children’s Hospital

  https://www.childrenshospital.org/conditions/sickle-cell-disease

  Sickle cell disease is an inherited blood disorder. […] The following are the most common ways a child can develop sickle cell disease: If both parents have sickle cell trait, each of their children will have a 25 percent chance of having sickle cell disease. If one parent has sickle cell disease and the other has sickle cell trait, each of their children will have a 50 percent chance of having sickle cell disease and a 50 percent chance of having sickle cell trait. If one parent has sickle cell disease and the other does not, all of their children will have sickle cell trait, but none of them will have sickle cell disease.

• #2 What is Sickling? | Meaning, Causes, & Consequences

  https://www.sparksicklecellchange.com/what-is-sickle-cell/what-is-sickling

  Sickling is when the hemoglobin inside red blood cells sticks or clumps together, causing the cell to become fragile, rigid, and crescent or sickle-shaped. […] In sickle cell, red blood cells are packed with hemoglobin sickle (HbS) proteins. HbS proteins are created due to having two copies of an abnormal HBB gene. […] The amount of HbS molecules you have compared with other forms of hemoglobin in the cell and their subsequent polymerization are the ultimate cause of sickling in red blood cells as well as the associated symptoms and complications of sickle cell.

• #2 Sickle cell anemia – Symptoms & causes – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/sickle-cell-anemia/symptoms-causes/syc-20355876

  Sickle cell anemia is caused by a change in the gene that tells the body to make hemoglobin. Hemoglobin is the iron-rich compound in red blood cells that allows these cells to carry oxygen from the lungs to the rest of the body. The hemoglobin associated with sickle cell anemia causes red blood cells to become rigid, sticky and misshapen. […] For a child to have sickle cell anemia, both parents must carry one copy of the sickle cell gene and pass both copies to the child. […] If only one parent passes the sickle cell gene to the child, that child will have the sickle cell trait. With one typical hemoglobin gene and one sickle cell gene, people with the sickle cell trait make both typical hemoglobin and sickle cell hemoglobin.

• #2 Sickle cell disease

  https://womenshealth.gov/a-z-topics/sickle-cell-disease

  Sickle cell disease is a group of red blood cell disorders that are passed down from your parents. This means that it is a genetic disease, and you are born with it. […] All red blood cells have hemoglobin, which makes the cell red and helps carry oxygen to different parts of the body. Red blood cells with normal hemoglobin are round and flexible. If you have sickle cell disease, your red blood cells have abnormal hemoglobin and are crescent- or sickle-shaped. […] Abnormal hemoglobin genes (sickle cell genes) run in families. Having two sickle cell genes causes sickle cell disease. If you get one sickle cell gene from each of your parents, then you have sickle cell disease. If you get one sickle cell gene and one normal gene from your parents, you have sickle cell trait. […] Red blood cells that are crescent- or sickle-shaped cannot slide smoothly through small blood vessels like normal, round red blood cells. Sickle cells can get stuck in small blood vessels and block blood flow to organs and tissues in the body. When organs do not get enough blood, they do not get enough oxygen. This can cause organ damage and pain. When organs are damaged, they do not work properly. Many of the complications or health problems caused by sickle cell disease are caused by organ damage or inflammation.

• #2 What is Sickle Cell? | Sickle Cell Speaks

  https://www.sicklecellspeaks.com/understanding-sickle-cell/what-is-sickle-cell

  Sickle cell is an inherited condition that is passed down from your parents the same way people get the color of their eyes, skin and hair. […] Sickle cell begins with hemoglobin, the part of the red blood cell that carries oxygen. […] When red blood cells sickle, they cant do their job of carrying oxygen throughout the body as well. […] The process of hemoglobin clumping together to form a long chain inside the red blood cells is called polymerization. This chain of hemoglobin is what causes the red blood cells to change into a sickled shape. […] Anemia, which is having too few red blood cells. […] It is unknown how much each of these components of sickle cell may impact your overall health. […] Sickle cell disease changes over time, impacting your overall health.

• #2 Azthena logo with the word Azthena

  https://www.news-medical.net/health/Sickle-Cell-Disease-Pathophysiology.aspx

  When there is insufficient oxygen in the vascular system, sickle hemoglobin becomes considerably more insoluble, increasing the polymer formation in the blood and its overall viscosity. […] Anemia can present due to hemolysis of the red blood cells with sickle hemoglobin in the spleen. As a result, the red blood cells have a shorter lifespan than normal, thus allowing for hemolytic anemia to potentially develop. […] Multiple organ damage can occur to patients with sickle hemoglobin over an extended period of time. This may affect the heart, skeleton, spleen, brain, eyes, lungs, kidneys, penis, and skin.

• #2 Sickle Cell Crisis: Types, Causes, Symptoms, Treatment

  https://www.verywellhealth.com/sickle-cell-crisis-5218258

  Sickle cell crisis is a health complication of sickle cell disease, an inherited blood disorder. […] There are several situations that can trigger a sickle cell crisis. For people who have sickle cell anemia, these changes can make the red blood cells prone to forming a sickle shape, and may also cause changes in small blood vessels, making it harder for blood to flow smoothly. […] Sickle-shaped red blood cells are not smooth like healthy red blood cells. Instead, they become sticky and prone to clumping together and blocking blood vessels anywhere in the body. […] Triggers for a sickle cell crisis include: Infections, Dehydration (loss of body fluids without adequate replacement), Cold temperature, Stress, Surgery or medical illness, Low oxygen. […] Preventive therapies can help reduce the severity and frequency of sickle cell crises for people who have sickle cell disease.

• #2 Sickle Cell Disease (SCD): Practice Essentials, Background, Genetics

  https://emedicine.medscape.com/article/205926-overview

  The sickling process that prompts a crisis may be precipitated by multiple factors. Local tissue hypoxia, dehydration secondary to a viral illness, or nausea and vomiting, all of which lead to hypertonicity of the plasma, may induce sickling. Any event that can lead to acidosis, such as infection or extreme dehydration, can cause sickling. More benign factors and environmental changes, such as fatigue, exposure to cold, and psychosocial stress, can elicit the sickling process. A specific cause is often not identified. […] Vaso-occlusive crises are often precipitated by the following: Cold weather (due to vasospasm), Hypoxia (eg, flying in unpressurized aircraft), Infection, Dehydration (especially from exertion or during warm weather), Acidosis, Alcohol intoxication, Emotional stress, Pregnancy. […] Aplastic crises are often preceded by the following: Infection with parvovirus B19, Folic acid deficiency, Ingestion of bone marrow toxins (eg, phenylbutazone). […] Acute chest syndrome has been linked to the following: Fat embolism, Infections, Pain episodes, Asthma.

• #2 Sickle Cell Crisis: Triggers, Prevention, and Management

  https://www.healthline.com/health/sickle-cell-crisis-triggers

  Sickle cell disease (SCD) is a genetic condition that affects the shape and function of your red blood cells (RBCs). […] However, if you have SCD, certain genetic mutations make your RBCs rigid and shaped like the letter C or a sickle. This makes it hard for RBCs to capture and carry enough oxygen. […] Scientists dont completely understand the exact causes of a sickle cell crisis. Most of the time, it happens because of a physical trigger, but it can also occur without a known cause. […] Most commonly, any triggers that cause your blood vessels to constrict can result in a sickle cell crisis. These triggers include: physical or psychological stress, cold weather, pain, alcohol, tobacco products, loss of fluids (dehydration), infection, low blood oxygen (hypoxemia), which can result from very strenuous exercise, high altitude, or certain medical conditions.

• #2 Sickle Cell Disease (Anemia): Symptoms, Treatment, and Life Expectancy

  https://www.medicinenet.com/sickle_cell/article.htm

  Sickle cell anemia (sickle cell disease) is a disorder of the blood caused by inherited abnormal hemoglobin (the oxygen-carrying protein within the red blood cells). The abnormal hemoglobin causes distorted (sickled appearing under a microscope) red blood cells. The sickled red blood cells are fragile and prone to rupture. When the number of red blood cells decreases from rupture (hemolysis), anemia is the result. This condition is referred to as sickle cell anemia. The irregular sickled cells can also block blood vessels causing tissue and organ damage and pain. […] Sickling of the red blood cells in patients with sickle cell anemia results in cells of abnormal shape and diminished flexibility. The sickling is promoted by conditions associated with low oxygen levels, increased acidity, or low volume (dehydration) of the blood. These conditions can occur because of injury to the body’s tissues, dehydration, or anesthesia.

• #2 Sickle Cell Crisis: Symptoms, Causes, Treatment, Prevention

  https://www.webmd.com/a-to-z-guides/sickle-cell-crisis

  Typically, you wont know why you had a crisis, and there may be more than one cause. Possible triggers include: […] Being at high altitudes (mountain climbing, for example) […] Changes in temperature, like if you go from a warm house into a cold winter day and you havent bundled up […] Infections […] Not having enough to drink (dehydration) […] Stress.

• #2 Overview of the pulmonary complications of sickle cell disease – UpToDate

  https://www.uptodate.com/contents/overview-of-the-pulmonary-complications-of-sickle-cell-disease/print

  Sickle cell anemia is caused by homozygous sickle mutation (Hb SS). The sickle mutation causes substitution of a valine for glutamic acid as the seventh amino acid of the beta globin chain. […] Etiologies include pulmonary vaso-occlusion and ischemia, pneumonia, fat embolization, and thrombosis (either intravascular or thromboembolic). Infection remains a significant cause of ACS, especially in children, and infectious etiologies are essential to investigate and treat.

• #2 What Can Trigger Sickle Cell Crisis? – BuzzRx

  https://www.buzzrx.com/blog/what-can-trigger-sickle-cell-crisis

  Sickle cell disease is an inherited autosomal recessive disorder. It occurs when a person inherits one copy of a defective gene from each parent. The gene involved in SCD affects hemoglobin formation in red blood cells. […] Sickle cells have a shorter lifespan than healthy red blood cells. These abnormal cells die within 10-20 days instead of the usual 120 days. This results in anemia and causes fatigue because there isn’t enough oxygen delivery by the sickle cell hemoglobin to various tissues in the body. […] In this type of sickle cell crisis, a viral infection temporarily suppresses RBC precursor cells in the marrow, causing worsening anemia. […] In this SCD crisis, a bacterial infection causes the spleen to enlarge rapidly, trapping red blood cells and preventing them from re-entering the circulation, causing worsening anemia. […] This sickle cell crisis is characterized by increased destruction of red blood cells due to infections, toxins, or certain drugs. […] Acute chest syndrome is a life-threatening complication of sickle cell disease that can be triggered by infections, asthma, and pain crises.

• #2 Sickle Cell Disease – Causes and Risk Factors | NHLBI, NIH

  https://www.nhlbi.nih.gov/health/sickle-cell-disease/causes

  Sickle cell disease is a genetic disorder caused by mutations in hemoglobin genes, leading to a faulty hemoglobin protein, called hemoglobin S. […] These genes make a faulty hemoglobin protein called hemoglobin S. Sickle cell disease can also occur when a child inherits a gene for hemoglobin S (a sickle cell gene) from one parent and a gene for a different type of faulty hemoglobin, such as beta thalassemia or hemoglobin C, from the other parent. […] Each time this couple has a child, the chances of the child having sickle cell disease remain the same. […] The disease is most common in people of African, Middle Eastern, Mediterranean, Central and South American, and South Asian origin or descent. […] Studies show that having the hemoglobin S gene protects against serious malaria. The malaria protection theory explains why the gene mutation leading to hemoglobin S is found more often among people whose ancestry traces to areas where malaria is common. […] Sickled red blood cells are not flexible and can stick to vessel walls, which can block or slow blood flow. […] This can lead to a low number of red blood cells, called anemia.

• #2 The Facts and Factors of Sickle Cell Anemia | Morehouse School of Medicine

  https://www.msm.edu/blog/2019/facts-and-factors-sickle-cell-anemia.php

  Sickle cell anemia is one of today’s most common inherited blood disorders. It affects several ethnic groups but predominantly Africans and African Americans, with approximately 90,000 to 100,000 Americans having the condition. Overall, it is estimated that sickle cell disease affects one in 500 U.S. African American births. […] The disease can only be inherited. In order to inherit sickle cell disease, both parents must have either sickle cell disease (two sickle cell genes) or sickle cell trait (one sickle cell gene). If you have sickle cell disease, you will pass one sickle cell gene on to your children. […] Sickle cell disease is more common among certain ethnic groups: People of African descent, including African Americans; Hispanic-Americans from Central and South America; People of Middle Eastern, Asian, Indian, and Mediterranean descent. […] Sickle cell disease symptoms can begin as early as four months of age so early diagnosis is critical. All newborns in the United States are now tested for the disease.

• #2 Sickle cell anemia Information | Mount Sinai – New York

  https://www.mountsinai.org/health-library/diseases-conditions/sickle-cell-anemia

  Sickle cell disease is caused by an abnormal type of hemoglobin called hemoglobin S. Hemoglobin is a protein inside red blood cells that carries oxygen. […] Sickle cell disease is inherited from both parents. If you get the sickle cell gene from only one parent, you will have sickle cell trait. People with sickle cell trait do not have the symptoms of sickle cell disease. […] Sickle cell disease is much more common in people of African and Mediterranean descent. It is also seen in people from South and Central America, the Caribbean, and the Middle East. […] Causes of death include organ failure and infection.

• #2 What is sickle cell anaemia?

  https://www.yourgenome.org/theme/what-is-sickle-cell-anaemia/

  Sickle cell anaemia is an inherited blood cell condition in which red blood cells develop atypically. […] Sickle cell anaemia is a recessive genetic condition that causes a persons haemoglobin the protein that carries oxygen around the body to become hard and sticky. This can cause the red blood cells to get stuck in blood vessels, leading to pain and other health problems. […] Its caused by a mutation in the HBB gene, found on chromosome 11. […] Sickle cell anaemia is caused by a mutation in a gene called haemoglobin beta (HBB), located on chromosome 11. […] It is a recessive genetic disease, which means that both copies of the gene must contain the mutation for a person to have sickle cell anaemia. […] If an individual has just one copy of the mutated gene, they are said to be a carrier of the sickle cell trait. If both biological parents are carriers, there is a chance their child could be born with sickle cell anaemia. […] We now know that sickle cell trait can also make the individual more resistant to malaria. This is because the mutation affects the haemoglobin enough to make it resistant to infection by the malaria-causing parasite, but not so much that it blocks the flow of blood.

• #2 Sickle Cell Disease (Anemia): Symptoms, Treatment, and Life Expectancy

  https://www.medicinenet.com/sickle_cell/article.htm

  Interestingly, the sickle cell gene somewhat protects against malaria infection. This makes those with sickle cell trait (gene carriers) at least partially resistant to malaria. Furthermore, the geographic distribution of the sickle cell gene is similar to that of malaria infection. Sickle cell anemia is a lethal condition that threatens life. However, there may be a selective advantage to being a sickle cell carrier (trait) if the person resides in an area of the world where malaria is very common. The advantage a person with sickle cell trait has over a non-carrier of the gene may explain why sickle cell anemia did not disappear from the world even though it is lethal. […] Sickle cell anemia is an inherited illness. Both parents must be carriers of the sickle cell gene for a child to be affected with sickle cell anemia. If each parent is a carrier, any child has a 1 in 2 chance (50%) of also being a carrier and a one in four (25%) chance of inheriting both genes from the parents and being affected with sickle cell anemia.

• #2 Sickle Cell Disease

  https://www.genome.gov/genetics-glossary/Sickle-Cell-Disease

  Sickle cell disease is a hereditary disease seen most often among people of African ancestry. Caused by mutations in one of the genes that encode the hemoglobin protein, the disease is inherited as an autosomal recessive trait. […] In studying the genomics of people from Africa, it’s very clear now that three different times during the history of the human race the mutation in the beta-globin gene that changes an amino acid at the sixth position of the protein, the same mutation has happened. […] The problems happen when the red cell containing hemoglobin S gets into the muscles or into your brain and discharges the oxygen. […] The difference between hemoglobin S and wild-type hemoglobin is that the wild-type hemoglobin is soluble when it’s got oxygen, and it’s also soluble when it doesn’t have oxygen.

• #2 Sickle Cell Anemia: Types, Symptoms, and Treatment

  https://www.healthline.com/health/sickle-cell-anemia

  Sickle cell anemia, or sickle cell disease (SCD), is a genetic disease of the red blood cells (RBCs). […] SCD is an autosomal recessive condition. You need two copies of the gene to have the disease. If you have only one copy of the gene, you are said to have sickle cell trait. […] The four main types of sickle cell anemia are caused by different mutations in these genes. […] Hemoglobin SS disease is the most common type of sickle cell disease. It occurs when you inherit copies of the hemoglobin S gene from both parents. […] Hemoglobin SC disease is the second most common type of sickle cell disease. It occurs when you inherit the Hb C gene from one parent and the Hb S gene from the other. […] Hemoglobin SB+ (beta) thalassemia affects beta globin gene production. […] Hemoglobin SB 0 (Beta-zero) thalassemia is the fourth type of sickle cell disease.

• #2 Sickle cell disease: causes, treatments and the patient experience – The Pharmaceutical Journal

  https://pharmaceutical-journal.com/article/ld/sickle-cell-disease-causes-treatments-and-the-patient-experience

  Sickle cell disease (SCD) is a general term for a group of inherited red blood cell disorders. Normal red blood cells have a biconcave disc shape that is flexible and can easily pass through blood vessels. However, those with SCD have abnormalities in their haemoglobin owing to genetic mutations, resulting in their red blood cells becoming ‘sickle’ shaped rather than round. This inhibits the cells’ ability to carry oxygen and can therefore restrict the amount of oxygen received by the limbs and organs. The cells are also rigid and sticky, causing the red blood cells to stick together, reducing their ability to move through the blood vessels easily. This can lead to blockages, which cause the patient significant pain. […] The most common types of SCD are HbSS, HbSC and HbS beta thalassaemia. HbSS SCD occurs when an individual inherits two genes that code for haemoglobin ‘S’, the abnormal form of haemoglobin that causes the sickle shape of the red blood cell. This type is often referred to as sickle cell anaemia and is the most severe form. HbSC SCD occurs when an individual inherits one haemoglobin ‘S’ and one haemoglobin ‘C’ gene. Both cause abnormal red cell shapes, but this is usually a milder form of SCD. HbS beta thalassaemia occurs when an individual inherits one ‘S’ gene and one beta thalassaemia gene; both genes cause abnormal red blood cell shapes.

• #2

• #2 Sickle cell disease – Wikipedia

  https://en.wikipedia.org/wiki/Sickle_cell_disease

  Sickle cell anemia results in an abnormality in the oxygen-carrying protein haemoglobin found in red blood cells. […] Sickle cell disease occurs when a person inherits two abnormal copies of the -globin gene that makes haemoglobin, one from each parent. […] The mutation which causes sickle cell disease results in an abnormal hemoglobin known as hemoglobin S (HbS), which replaces HbA in adults. […] The gene defect is a single nucleotide mutation of the -globin gene, which results in glutamate being substituted by valine at position 6 of the -globin chain. […] The sickle cell trait provides a carrier with a survival advantage against malaria fatality over people with normal hemoglobin in regions where malaria is endemic. […] Sickle cell disease has an autosomal recessive pattern of inheritance from parents. […] If both parents are carriers for the autosomal recessive gene, there is a 25% chance of their child having and expressing the disorder.

• #3 Causes of Sickle Cell Disease | Sickle Cell Disease NewsEnvelope icon

  https://sicklecellanemianews.com/causes-sickle-cell-disease/

  Sickle cell disease comprises a group of rare genetic disorders in which red blood cells adopt a sickle-like shape and die prematurely, resulting in fewer red blood cells available to carry oxygen throughout the body. […] Sickle cell disease is caused by mutations in the beta-globin (HBB) gene that lead to the production of an abnormal version of a subunit of hemoglobin — the protein responsible for carrying oxygen in red blood cells. […] Sickle cell disease is considered an autosomal recessive disorder, meaning that a person must receive two defective gene copies — one from each parent — to develop the condition. […] When both copies of the gene encode hemoglobin S, a person is said to have sickle cell anemia, the most common and often the most severe form of sickle cell disease. […] Other types of sickle cell disease arise from having a mutated HBB copy encoding hemoglobin S and a different mutation resulting in the production of another faulty version of hemoglobin, such as hemoglobin C.

• #3

  https://journals.lww.com/md-journal/fulltext/2023/09220/understanding_sickle_cell_disease__causes,.30.aspx

  SCD is primarily caused by a genetic mutation affecting hemoglobin, the protein responsible for carrying oxygen in red blood cells. The underlying cause of SCD lies in a point mutation in the HBB on chromosome 11, resulting in the production of abnormal hemoglobin known as HbS. […] The specific mutation involves a substitution of a single nucleotide, where adenine is replaced by thymine, leading to the substitution of glutamic acid with valine at the sixth position of the beta-globin chain. […] This alteration affects the structure and function of hemoglobin, causing it to polymerize under certain conditions, such as low oxygen tension or dehydration. […] The polymerization of HbS leads to the deformation of red blood cells into a characteristic sickle shape, which is rigid and prone to hemolysis.

• #3 Sickle Cell Disease | Lehigh Valley Health Network

  https://www.lvhn.org/conditions/sickle-cell-disease

  Sickle cell disease is an inherited blood disorder characterized by defective hemoglobin (a protein in red blood cells that carries oxygen to the tissues of the body). […] Sickle cell is an inherited disease caused by a genetic mutation. […] A mutation or error in this gene is what causes sickle cell disease. […] This mutation is thought to have originated in areas of the world where malaria was common, since people with sickle trait tolerate malaria better and have a reproductive advantage in areas with malaria. […] Sickle cell (HbSS) is a genetic disease. […] A person will be born with sickle cell disease only if two HbS genes are inherited – one from the mother and one from the father. […] A person who has only one HbS gene is healthy and said to be a „carrier” of the disease.

• #3 What Can Trigger Sickle Cell Crisis? – BuzzRx

  https://www.buzzrx.com/blog/what-can-trigger-sickle-cell-crisis

  Sickle cell disease is an inherited autosomal recessive disorder. It occurs when a person inherits one copy of a defective gene from each parent. The gene involved in SCD affects hemoglobin formation in red blood cells. […] Sickle cells have a shorter lifespan than healthy red blood cells. These abnormal cells die within 10-20 days instead of the usual 120 days. This results in anemia and causes fatigue because there isn’t enough oxygen delivery by the sickle cell hemoglobin to various tissues in the body. […] In this type of sickle cell crisis, a viral infection temporarily suppresses RBC precursor cells in the marrow, causing worsening anemia. […] In this SCD crisis, a bacterial infection causes the spleen to enlarge rapidly, trapping red blood cells and preventing them from re-entering the circulation, causing worsening anemia. […] This sickle cell crisis is characterized by increased destruction of red blood cells due to infections, toxins, or certain drugs. […] Acute chest syndrome is a life-threatening complication of sickle cell disease that can be triggered by infections, asthma, and pain crises.

• #3

  https://journals.lww.com/md-journal/fulltext/2023/09220/understanding_sickle_cell_disease__causes,.30.aspx

  SCD follows an autosomal recessive inheritance pattern, meaning an individual must inherit 2 copies of the mutated gene (one from each parent) to develop the disease. […] The prevalence of SCD is higher in populations with a historical association with malaria, as the sickle cell trait provides some protection against severe forms of malaria infection. […] Understanding the genetic basis and underlying cause of SCD has paved the way for advancements in genetic counseling and carrier screening programs.

• #4

  https://journals.lww.com/md-journal/fulltext/2023/09220/understanding_sickle_cell_disease__causes,.30.aspx

  SCD is primarily caused by a genetic mutation affecting hemoglobin, the protein responsible for carrying oxygen in red blood cells. The underlying cause of SCD lies in a point mutation in the HBB on chromosome 11, resulting in the production of abnormal hemoglobin known as HbS. […] The specific mutation involves a substitution of a single nucleotide, where adenine is replaced by thymine, leading to the substitution of glutamic acid with valine at the sixth position of the beta-globin chain. […] This alteration affects the structure and function of hemoglobin, causing it to polymerize under certain conditions, such as low oxygen tension or dehydration. […] The polymerization of HbS leads to the deformation of red blood cells into a characteristic sickle shape, which is rigid and prone to hemolysis.

• #5 Sickle Cell Disease in Children – Stanford Medicine Children’s Health

  https://deprod.stanfordchildrens.org/en/topic/default?id=sickle-cell-disease-in-children-90-P02327

  Sickle cell is present at birth. It is inherited when a child has 2 sickle cell genes, 1 from each parent. […] A child who has only one sickle cell gene is healthy. But he or she is a carrier of the disease. If two carriers have a child, there is a greater chance their child will have sickle cell disease. […] Once parents have had a child with sickle cell disease, there is a 1 in 4 chance that another child will be born with sickle cell disease. There is also a 1 in 2 chance that a child will be a carrier, like the parents.

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