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

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

  Sickle cell disease affects the hemoglobin within your red blood cells. A genetic mutation causes abnormal hemoglobin to clump together, causing the red blood cells to turn sickle shaped. […] Sickle cell disease (SCD) is the most common inherited blood disorder that affects your red blood cells. In SCD, a protein called hemoglobin, located within red blood cells, is abnormal. […] A genetic mutation in the HBB gene causes sickle cell disease. The HBB gene is responsible for making a part of the hemoglobin. People with SCD received two mutated HBB genes coded for abnormal hemoglobin one from each parent. […] People inherit SCD in an autosomal recessive manner. This means each parent of a child with SCD carries one copy of the mutated gene, but they typically dont show signs and symptoms of the condition.

• #1 Sickle cell disease – Wikipedia

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

  Sickle cell disease occurs when a person inherits two abnormal copies of the -globin gene that makes haemoglobin, one from each parent. […] Causes Genetic, Homozygous mutation in the hemoglobin S gene. […] 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 mutation which causes sickle cell disease results in an abnormal hemoglobin known as hemoglobin S (HbS), which replaces HbA in adults. […] Sickle cell disease has an autosomal recessive pattern of inheritance from parents. […] This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. […] If both parents are carriers for the autosomal recessive gene, there is a 25% chance of their child having and expressing the disorder. […] There are several different haplotypes of the sickle cell gene mutation, indicating that it probably arose spontaneously in different geographic areas.

• #1

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

  Sickle cell disease (SCD) is primarily caused by a mutation in the gene responsible for producing hemoglobin, known as the beta-globin gene (HBB) gene. […] The primary cause of SCD is a mutation in the gene responsible for producing hemoglobin, the protein that carries 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. […] 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.

• #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.

• #1

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

  Sickle cell disease is caused by inheriting the sickle cell gene. […] It’s not caused by anything the parents did before or during the pregnancy and you cannot catch it from someone who has it. […] To be born with sickle cell disease, a child has to inherit a copy of the sickle cell gene from both their parents. […] This usually happens when both parents are „carriers” of the sickle cell gene, also known as having the sickle cell trait. […] Or it can happen when 1 parent has sickle cell disease and the other is a carrier of it. […] Sickle cell carriers do not have sickle cell disease themselves, but there’s a chance they could have a child with sickle cell disease if their partner is also a carrier. […] If both parents are sickle cell carriers, there’s a: 1 in 4 chance each child they have will inherit copies of the sickle cell gene from both parents and will be born with sickle cell disease.

• #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 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

  The mutation in beta-globin causes hemoglobin to cluster together and misshape the red blood cells. This leads to the symptoms and complications experienced by people with SCD. […] SCD is a recessive trait because people must inherit 2 copies of the mutated HBB allele to show symptoms. The most common form of this is sickle cell anemia, which occurs when someone inherits 2 copies of the sickle HBB allele. […] There are 3 ways that can lead to a child having SCD: If both parents have sickle cell trait […] If 1 parent has SCD and 1 parent has sickle cell trait […] If both parents have SCD […] The HBB gene is located on chromosome number 11. This is not the sex chromosome, so SCD is not a sex-linked disease. This means that both men and women can get SCD.

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

  https://medlineplus.gov/sicklecelldisease.html

  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.

• #1 Overview of the clinical manifestations of sickle cell disease – UpToDate

  https://www.uptodate.com/contents/overview-of-the-clinical-manifestations-of-sickle-cell-disease

  The sickle point mutation (sickle cell variant) in the beta-globin gene produces sickle hemoglobin (Hb S), which is less soluble than fetal or adult hemoglobins. […] Sickle cell disease (SCD) refers to any syndrome in which the sickle mutation is coinherited with a pathogenic variant at the other beta-globin allele that reduces or abolishes normal beta-globin production. These include sickle cell anemia (homozygous sickle mutation [Hb SS]), sickle-beta thalassemia, hemoglobin SC disease, and others. […] The key feature of all types of SCD is that the Hb S proportion is typically >50 percent, and Hb S is the predominant hemoglobin. […] The clinical manifestations of SCD are protean. The major features are related to hemolytic anemia and vaso-occlusion, which can lead to acute and chronic pain and tissue ischemia or infarction. […] Splenic infarction leads to functional hyposplenism early in life, increasing the risk of infection. […] These complications have a major impact on morbidity and mortality.

• #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. […] 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). […] People who have SCT inherit one sickle cell gene (S) from one parent and one normal gene (A) from the other parent.

• #1 Children with Sickle Cell, Disease Symptoms, Causes and Treatments | Children’s Hospital Los Angeles

  https://www.chla.org/sickle-cell-disease

  Sickle cell disease is caused by mutations in a specific gene (hemoglobin-beta gene) that result in abnormally shaped red blood cells. […] Children must receive the hemoglobin-beta gene from both parents to develop the disease. […] SCD is the most common inherited blood disorder in the U.S., especially among Black children. About 1 in 365 Black babies are born with SCD each year. However, SCD affects people of all ethnicities.

• #1 How Sickle Cell Disease and Malaria Defined Evolution | Global Health NOW

  https://globalhealthnow.org/2024-06/how-sickle-cell-disease-and-malaria-defined-evolution

  Sickle cell disease affects more than 20 million people worldwide and can be a devastating condition. […] The inherited blood disorder affects the hemoglobin that carries oxygen through the body. It results in hard, sticky, banana or sickle-shaped cells that stick together, stifling the flow of oxygen. […] The sickle cell gene evolved in Africa approximately 20,000 years ago, but there is still much to learn from the diseases ancient genetic link to malaria. […] From time to time, humans have spontaneous mutations in our genes. And some 20,000 years ago, one of those mutations—the mutation for sickle cell disease—happened to be protective against malaria. […] If you have one copy of that sickle cell mutation, hemoglobin-S, you are a carrier. You will not become sick from sickle cell disease, and you’ll be very resistant to malaria. But if you have a double copy, one from each parent, you have sickle cell disease.

• #1 How Sickle Cell Disease and Malaria Defined Evolution | Global Health NOW

  https://globalhealthnow.org/2024-06/how-sickle-cell-disease-and-malaria-defined-evolution

  As Africa’s population evolved, those without the single mutation would often die of malaria, and those who had two copies of the gene would die of sickle cell disease. That’s why the single mutation became extremely common in Africa as populations settled, became more agriculturalist, and expanded. […] We know the sickle cell mutation confers itself to malaria, but we don’t know exactly how. […] One theory is that when malaria infects red blood cells that have the sickle cell mutation, it doesn’t grow well as a parasite and will not reproduce itself easily. […] Another theory is that once hemoglobin-S—the protein that causes sickle cell disease—is infected with malaria, it is quickly eliminated from the blood and that malaria parasite will not grow. […] Now researchers hypothesize that the same co-evolution may have happened with malaria. It is possible that at some point, malaria also developed a mutation to be tolerant to humans.

• #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.

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

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

  Sickled red blood cells are not flexible and can stick to vessel walls, which can block or slow blood flow. […] The body is always making new red blood cells to replace the old cells. However, in sickle cell disease, the body has trouble keeping up with the rate that the cells are being destroyed.

• #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 Sickle Cell Disease: Causes, Symptoms, and Treatment

  https://patient.info/allergies-blood-immune/sickle-cell-disease-sickle-cell-anaemia

  Sickle cell disease (SCD) is a serious, inherited condition affecting the blood and various organs in the body. […] The cause is inherited (genetic). It is a change in the genes which tell the body how to make an important protein called haemoglobin. To get SCD, you need to have two altered haemoglobin genes, one from each parent. […] The most common type of sickle cell disease occurs where you have two sickle cell genes (sickle cell anaemia). […] Sickle cell genes affect the production of an important chemical called haemoglobin. […] The sickle cell genes make the body produce abnormal haemoglobin called HbS. […] This is called sickling. Conditions which trigger sickling are cold, infection, lack of fluid in the body (dehydration), low oxygen, and acid (acid is produced in hard physical exercise). […] The symptoms, diagnosis and treatment are similar for all the sickle cell conditions. […] The treatment of sickle cell anaemia is a developing area of medicine. New treatments continue to be developed and the information on outlook above is very general.

• #1 Sickle Cell Anemia: Symptoms, Treatment, Causes & Inheritance

  https://www.emedicinehealth.com/sickle_cell_crisis/article_em.htm

  Sickle cell disease results from mutation, or change, of certain types of hemoglobin chains in red blood cells (the beta hemoglobin chains). […] The changes in the building of normal hemoglobin result in the abnormal hemoglobin of sickle cell disease. These mutated molecules do not have the smooth motion needed for oxygenation and deoxygenation. When the oxygen concentration in the blood is reduced, the red blood cell assumes the characteristic sickle shape. This causes the red blood cells to be stiff and rigid and stops the smooth passage of the red blood cells through the narrow blood vessels. […] It does not take much imagination to see sharp-end „sickled” red cells stacking up in narrow blood vessels known as capillaries. When this happens, red blood cells are not able to carry oxygen to tissues, and tissue cell injury or death occurs. Someone with sickle cell disease would be experiencing pain with this process-the sickle cell crisis.

• #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

  SCD is associated with both acute and long-term complications that necessitate a comprehensive, multidisciplinary approach. People with SCD face an elevated risk of developing complications in their lungs, heart and kidney function, primarily owing to reduced blood and oxygen supply to these vital organs. […] SCD is also associated with hypersplenism, a condition in which the sequestration of sickle red blood cells in the spleen leads to splenomegaly. The reduction in splenic function renders patients more susceptible to life-threatening infections, such as influenza, meningitis and pneumonia. […] There are limited long-term treatment options for patients with SCD. Hydroxycarbamide (hydroxyurea) is an oral medication that has been shown to reduce the frequency and severity of acute sickle cell crisis and acute chest syndrome (a complication of SCD). The exact mechanism of action of the medicine is unknown; however, in SCD, it is thought to elevate foetal haemoglobin, which interferes with the polymerisation of sickle haemoglobin, preventing the sickling of red blood cells.

• #1 Sickle Cell Disease

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

  However, though, short polymers are very, very dangerous. […] And so it’s very unfortunate that about one-third of people who are homozygous for hemoglobin S will have one or more strokes before they’re 10 years old. […] And it is simply amazing to me that this all comes from one very small change, changes in amino acid, that really isn’t having any effect on the normal function of the protein, but has big effects on all of the other systems in the body that the red cells pass through.

• #1 Sickle Cell Disease, a Review

  https://www.mdpi.com/2673-6357/3/2/24

  There is a significant variation in symptomatology of the disease based on a number of variables, including coinheritance of genetic factors which can enhance or reduce the severity of the symptoms. […] Higher levels of fetal hemoglobin, association with other hemoglobins, coinheritance with α-thalassemia, and certain genetic factors can potentially result in a milder disease. […] The disease results in a number of major events, most, but not all of which originate from a coherent pathophysiological scheme based on the abnormal polymerization of deoxy-hemoglobin S. […] While polymerization results in erythrocyte injury and sickling, multiple other factors are also involved. […] The pathophysiology of the SCD is complex and multi-systemic. […] Sickle cell disease is a complex genetic blood disorder that affects multiple organs and systems.

• #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

  Stem cell and bone marrow transplants are currently the only established cure for SCD, but they are not performed often because of the significant risks involved; these include infection, graft-versus-host disease and organ injury from the conditioning regimen, which involves immunosuppressive medications and low-dose radiotherapy.

• #1 Sickle Cell Anemia: Genetics, Chronic Symptoms, Support

  https://www.verywellhealth.com/sickle-cell-anemia-7507053

  Sickle cell disease is an inherited condition that affects the oxygen-carrying hemoglobin protein in red blood cells. […] Sickle cell anemia results from a genetic mutation (alteration) in the HBB gene that codes for the hemoglobin protein. […] This gene is inherited from your parents. […] If a child inherits the gene mutation for HbS from you and a hemoglobin gene mutation from the other parent, they will have sickle cell disease. […] Sickle cell disease can result from mutations within different parts of the HBB gene. […] Sickle cell disease is more common among certain populations. […] There is no cure for sickle cell disease, however, bone marrow transplant has been considered a potential curative therapy. […] Gene therapies include Casgevy (exagamglogene autotemcel) and Lyfgenia (lovotibeglogene autotemcel). […] These treatments are not a cure for sickle cell anemia but are designed to be a one-time treatment to alleviate symptoms for a lifetime.

• #1 Sickle Cell Anemia | Sepsis Alliance

  https://www.sepsis.org/sepsisand/sickle-cell-anemia/

  Sickle cell anemia is a common inherited blood disease that causes red blood cells to form into a curved or sickle shape. […] Sickle cell anemia affects about 1 out of every 365 Black or African-American births and 1 out of every 16,300 Hispanic-American births. […] People with the disease have a higher risk of contracting infections that, in turn, could cause sepsis. […] The misshapen red blood cells also damage the body’s organs, including the spleen. […] This means fewer red blood cells are available to carry oxygen and nutrients throughout the body. This adds to the infection risk. […] The only cure known for sickle cell anemia is a bone marrow transplant and it is only performed in children. […] People with sickle cell anemia are at high risk for severe COVID-19. […] Infection prevention for people with sickle cell anemia is essential. […] According to the CDC, people with sickle cell anemia are particularly affected by salmonella bacteria. […] Children with sickle cell anemia often take preventative (prophylactic) penicillin every day up to the age of five. This is to prevent infections.

• #2 Understanding Sickle cell disease: Causes, symptoms, and treatment options – PubMed

  https://pubmed.ncbi.nlm.nih.gov/37746969/

  Sickle cell disease (SCD) is a hereditary blood disorder characterized by the production of abnormal hemoglobin molecules that cause red blood cells to take on a crescent or sickle shape. […] The primary cause of SCD is a mutation in the gene responsible for producing hemoglobin, the protein that carries oxygen in red blood cells. […] This mutation has abnormal hemoglobin called hemoglobin S, which causes red blood cells to become stiff and sticky, leading to various health complications.

• #2 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.

• #2 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 disease (a hemoglobinopathy) causes a chronic hemolytic anemia occurring commonly in people with African ancestry. 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. Hemoglobin S was the first abnormal hemoglobin to be identified. 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. […] In hemoglobin S, valine is substituted for glutamic acid in the sixth amino acid of the beta chain. Deoxygenated Hb S is much less soluble than oxygenated Hb A; it polymerizes and forms a semisolid gel that causes red blood cells (RBCs) to deform into a sickle shape at sites of low partial pressure of oxygen (PO2).

• #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 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.

• #2 Sickle Cell Disease (for Parents) | Nemours KidsHealth

  https://kidshealth.org/en/parents/sickle-cell-anemia.html

  Sickle cell disease is a group of conditions passed down in families through their genes. […] The type of sickle cell disease a person has depends on the hemoglobin genes each parent passes down to them. […] Someone with sickle cell disease has at least one sickle cell gene. […] The genes cause the body to make hemoglobin that causes the red blood cells to become sickle shaped. […] A child who gets two sickle cell genes, one from each parent, will have sickle cell disease. […] A child who gets a sickle cell gene from one parent and a normal hemoglobin gene from the other parent has sickle cell trait. […] Someone who gets a sickle cell gene from one parent and another kind of abnormal gene from the other parent may have a different form of sickle cell disease, such as hemoglobin SC disease or sickle beta thalassemia.

• #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 Sickle Cell Disease | Cooper University Health Care

  https://www.cooperhealth.org/services/sickle-cell-disease

  SCD occurs when an individual inherits the sickle cell trait (SCT) from both parents. […] The increased occurrence of the condition among Black individuals can be explained by human evolution. In regions of Africa where malaria is prevalent, bodies have adapted to form sickle cells as a defense against the disease. […] Individuals with HbSS SCD inherited the sickle cell gene from both parents. […] Sickle cell anemia happens when the body has chronically low oxygen levels, causing organ complications and other health issues. […] Individuals with HbS beta thalassemia SCD inherit one hemoglobin S gene and another form of hemoglobin abnormality beta thalassemia from the other parent.

• #2 Sickle Cell Disease, a Review

  https://www.mdpi.com/2673-6357/3/2/24

  The most severe SCD genotypes have two βS alleles (βS/βS), however, there are other combinations of SCD genotypes. […] The βS allele combined with a null HBB allele (Hbβ0) and no protein translation results in HbSβ0-thalassemia. […] The βS allele combined with a hypomorphic HBB allele (Hbβ+ with a decreased amount of normal β-globin protein) results in HbSβ+-thalassemia disorder, which is generally milder than sickle cell disease.

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

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

  Sickle cell disease refers to a group of genetic disorders that affect hemoglobin. […] 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. […] 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. […] Sickle cell disease can affect anyone, but it is more common among Black people. […] People with sickle cell disease or sickle cell trait cannot give blood, but healthcare professionals encourage anyone who can donate to do so. […] Scientists are currently looking for a cure that will help all people with sickle cell disease.

• #2 Sickle Cell Anemia | Sepsis Alliance

  https://www.sepsis.org/sepsisand/sickle-cell-anemia/

  Sickle cell anemia is a common inherited blood disease that causes red blood cells to form into a curved or sickle shape. […] Sickle cell anemia affects about 1 out of every 365 Black or African-American births and 1 out of every 16,300 Hispanic-American births. […] People with the disease have a higher risk of contracting infections that, in turn, could cause sepsis. […] The misshapen red blood cells also damage the body’s organs, including the spleen. […] This means fewer red blood cells are available to carry oxygen and nutrients throughout the body. This adds to the infection risk. […] The only cure known for sickle cell anemia is a bone marrow transplant and it is only performed in children. […] People with sickle cell anemia are at high risk for severe COVID-19. […] Infection prevention for people with sickle cell anemia is essential. […] According to the CDC, people with sickle cell anemia are particularly affected by salmonella bacteria. […] Children with sickle cell anemia often take preventative (prophylactic) penicillin every day up to the age of five. This is to prevent infections.

• #2 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 is a genetic condition that people are born with, so there isn’t a way to prevent 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. […] Both sickle cell and thalassemia are inherited genetic disorders caused by a mutation in hemoglobin genes, the substance that carries oxygen in red blood cells.

• #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.

• #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 | WHO | Regional Office for Africa

  https://www.afro.who.int/health-topics/sickle-cell-disease

  Sickle cell disease (SCD), or sickle cell anaemia, is a major genetic disease that affects most countries in the African Region. In sickle cell disease, the normal round shape of red blood cells become like crescent moons. Round red blood cells can move easily through the blood vessels but sickled shaped cells interconnect and can result in blood clots. […] Environmental factors often play a role in the occurrence of painful attacks. Common triggers include cold temperatures, dehydration, excessive amounts of exercise and tobacco smoke. Other triggers such as plane flights and high altitudes can also trigger an attack. […] Sickle-cell disease is characterized by a modification in the shape of the red blood cell from a smooth, donut-shape into a crescent or half moon shape. The misshapen cells lack plasticity and can block small blood vessels, impairing blood flow. This condition leads to shortened red blood cell survival, and subsequent anaemia, often called sickle-cell anaemia.

• #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

  SCD is associated with both acute and long-term complications that necessitate a comprehensive, multidisciplinary approach. People with SCD face an elevated risk of developing complications in their lungs, heart and kidney function, primarily owing to reduced blood and oxygen supply to these vital organs. […] SCD is also associated with hypersplenism, a condition in which the sequestration of sickle red blood cells in the spleen leads to splenomegaly. The reduction in splenic function renders patients more susceptible to life-threatening infections, such as influenza, meningitis and pneumonia. […] There are limited long-term treatment options for patients with SCD. Hydroxycarbamide (hydroxyurea) is an oral medication that has been shown to reduce the frequency and severity of acute sickle cell crisis and acute chest syndrome (a complication of SCD). The exact mechanism of action of the medicine is unknown; however, in SCD, it is thought to elevate foetal haemoglobin, which interferes with the polymerisation of sickle haemoglobin, preventing the sickling of red blood cells.

• #2 Sickle cell disease – Wikipedia

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

  Sickle cell disease occurs when a person inherits two abnormal copies of the -globin gene that makes haemoglobin, one from each parent. […] Causes Genetic, Homozygous mutation in the hemoglobin S gene. […] 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 mutation which causes sickle cell disease results in an abnormal hemoglobin known as hemoglobin S (HbS), which replaces HbA in adults. […] Sickle cell disease has an autosomal recessive pattern of inheritance from parents. […] This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. […] If both parents are carriers for the autosomal recessive gene, there is a 25% chance of their child having and expressing the disorder. […] There are several different haplotypes of the sickle cell gene mutation, indicating that it probably arose spontaneously in different geographic areas.

• #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

  Stem cell and bone marrow transplants are currently the only established cure for SCD, but they are not performed often because of the significant risks involved; these include infection, graft-versus-host disease and organ injury from the conditioning regimen, which involves immunosuppressive medications and low-dose radiotherapy.

• #2 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

  The homozygous state is differentiated from other hemoglobinopathies by electrophoresis showing only Hb S with a variable amount of Hb F. The heterozygous state is differentiated by the presence of more Hb A than Hb S on electrophoresis. […] Hematopoietic stem cell transplantation remains the only curative treatment for sickle cell disease. Given the risks associated with this therapy, it is generally restricted to patients with advanced disease complications. […] Gene therapy or gene editing techniques that increase the amount of Hb F recently became available. This field is rapidly evolving, and use of stem cell therapy to treat sickle cell disease will likely continue to expand.

• #2 How Sickle Cell Disease and Malaria Defined Evolution | Global Health NOW

  https://globalhealthnow.org/2024-06/how-sickle-cell-disease-and-malaria-defined-evolution

  Sickle cell disease affects more than 20 million people worldwide and can be a devastating condition. […] The inherited blood disorder affects the hemoglobin that carries oxygen through the body. It results in hard, sticky, banana or sickle-shaped cells that stick together, stifling the flow of oxygen. […] The sickle cell gene evolved in Africa approximately 20,000 years ago, but there is still much to learn from the diseases ancient genetic link to malaria. […] From time to time, humans have spontaneous mutations in our genes. And some 20,000 years ago, one of those mutations—the mutation for sickle cell disease—happened to be protective against malaria. […] If you have one copy of that sickle cell mutation, hemoglobin-S, you are a carrier. You will not become sick from sickle cell disease, and you’ll be very resistant to malaria. But if you have a double copy, one from each parent, you have sickle cell disease.

• #2 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 development and testing of gene and cell therapies for sickle cell disease is still an ongoing effort of many scientists and companies.

• #3 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.

• #3

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

  Sickle cell disease (SCD) is primarily caused by a mutation in the gene responsible for producing hemoglobin, known as the beta-globin gene (HBB) gene. […] The primary cause of SCD is a mutation in the gene responsible for producing hemoglobin, the protein that carries 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. […] 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.

• #3 Sickle Cell Disease, a Review

  https://www.mdpi.com/2673-6357/3/2/24

  Sickle cell disease and its variants constitute the most common inherited blood disorders affecting millions of individuals worldwide. […] Significant information regarding the nature of the genetic mutations and modifier genes that result in increased or decreased severity of the disease are available. […] The term sickle cell disease encompasses a group of common inherited genetic disorders characterized by a point mutation involving the gene which encodes the hemoglobin subunit β (HBB). […] Genetic changes include homozygous missense mutation [Glu6Val, rs334] in the β-globin gene which upon deoxygenation results in polymerization of hemoglobin S (Hb S). […] Polymerization of the two-mutant sickle β-globin subunits leads to erythrocytes assuming a crescent or sickled shape, thus the designation of sickle cell disease (SCD).

• #3

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

  Sickle cell disease is caused by inheriting the sickle cell gene. […] It’s not caused by anything the parents did before or during the pregnancy and you cannot catch it from someone who has it. […] To be born with sickle cell disease, a child has to inherit a copy of the sickle cell gene from both their parents. […] This usually happens when both parents are „carriers” of the sickle cell gene, also known as having the sickle cell trait. […] Or it can happen when 1 parent has sickle cell disease and the other is a carrier of it. […] Sickle cell carriers do not have sickle cell disease themselves, but there’s a chance they could have a child with sickle cell disease if their partner is also a carrier. […] If both parents are sickle cell carriers, there’s a: 1 in 4 chance each child they have will inherit copies of the sickle cell gene from both parents and will be born with sickle cell disease.

• #3 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.

• #3

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

  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.

• #3 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

  The homozygous state is differentiated from other hemoglobinopathies by electrophoresis showing only Hb S with a variable amount of Hb F. The heterozygous state is differentiated by the presence of more Hb A than Hb S on electrophoresis. […] Hematopoietic stem cell transplantation remains the only curative treatment for sickle cell disease. Given the risks associated with this therapy, it is generally restricted to patients with advanced disease complications. […] Gene therapy or gene editing techniques that increase the amount of Hb F recently became available. This field is rapidly evolving, and use of stem cell therapy to treat sickle cell disease will likely continue to expand.

• #3 Causes of Sickle Cell Disease: Comprehensive Guide | Dr. Rahul

  https://www.drrahulbhargavahematologist.com/exploring-the-causes-of-sickle-cell-disease-a-comprehensive-guide/

  Sickle Cell Disease (SCD) is a serious genetic blood disorder that affects millions of people worldwide. Understanding its causes is key to managing the disease and improving patients quality of life. […] The primary cause of sickle cell disease is a mutation in the hemoglobin-beta gene found on chromosome 11. This mutation results in the production of abnormal hemoglobin known as hemoglobin S (HbS). […] SCD is inherited in an autosomal recessive pattern, which means both parents must carry the mutated gene for their child to develop the disease. […] While the genetic mutation is the primary cause of sickle cell disease, certain environmental and lifestyle factors can trigger complications. […] Sickle cell disease is more prevalent in certain ethnic groups, particularly those whose ancestors came from regions where malaria was or still is common.

• #3 How Sickle Cell Disease and Malaria Defined Evolution | Global Health NOW

  https://globalhealthnow.org/2024-06/how-sickle-cell-disease-and-malaria-defined-evolution

  As Africa’s population evolved, those without the single mutation would often die of malaria, and those who had two copies of the gene would die of sickle cell disease. That’s why the single mutation became extremely common in Africa as populations settled, became more agriculturalist, and expanded. […] We know the sickle cell mutation confers itself to malaria, but we don’t know exactly how. […] One theory is that when malaria infects red blood cells that have the sickle cell mutation, it doesn’t grow well as a parasite and will not reproduce itself easily. […] Another theory is that once hemoglobin-S—the protein that causes sickle cell disease—is infected with malaria, it is quickly eliminated from the blood and that malaria parasite will not grow. […] Now researchers hypothesize that the same co-evolution may have happened with malaria. It is possible that at some point, malaria also developed a mutation to be tolerant to humans.

• #3 Causes of Sickle Cell Disease: Comprehensive Guide | Dr. Rahul

  https://www.drrahulbhargavahematologist.com/exploring-the-causes-of-sickle-cell-disease-a-comprehensive-guide/

  As of now, there is no way to prevent sickle cell disease, as it is an inherited genetic condition. […] Understanding the causes of sickle cell disease is vital for effective management and prevention of complications. While the genetic mutation is the primary cause, environmental and lifestyle factors also play a significant role in the severity of the condition.

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