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	'''Sickle cell disease''' is a group of inherited blood conditions that affect haemoglobin, the protein in red blood cells that carries oxygen. The best-known form is sickle cell anaemia. In sickle cell disease, red blood cells can become stiff and sickle-shaped, making them more likely to break down and block small blood vessels.

Sickle Cell Disease (SCD) is a group of inherited blood disorders characterized by abnormal hemoglobin, a protein responsible for carrying oxygen in red blood cells. Individuals with SCD have red blood cells that become rigid and assume a sickle-like shape, impairing their ability to flow smoothly through blood vessels. This can lead to a range of complications and health problems.
	The condition can cause painful crises, anaemia, infection risk and organ complications. Severity varies widely. Some people have frequent hospital admissions, while others have milder disease with fewer symptoms.

== Overview ==
Sickle Cell Disease is most prevalent in individuals of African, Mediterranean, Middle Eastern, and Indian descent. It is estimated that approximately 300,000 babies are born with SCD each year worldwide, with the majority of cases occurring in sub-Saharan Africa.
	== Inheritance ==
	Sickle cell disease is inherited when a child receives a sickle cell gene from both parents. A person with one sickle cell gene is usually described as having sickle cell trait or being a carrier.

SCD is caused by a mutation in the gene that produces hemoglobin. This genetic alteration results in the production of abnormal hemoglobin known as hemoglobin S (HbS), which can cause red blood cells to become stiff and distorted under certain conditions.
	Carrier status does not usually cause sickle cell disease, but it matters for family planning. If both parents are carriers, each pregnancy has a chance of producing a child with sickle cell disease.

== Types of Sickle Cell Disease ==
There are several forms of Sickle Cell Disease, including:
	== Symptoms ==
	Symptoms can start from a few months of age. Main problems include painful episodes, increased infections and anaemia.

* Sickle Cell Anemia (HbSS): This is the most common and severe form of SCD. Individuals with sickle cell anemia inherit two copies of the abnormal hemoglobin gene (HbS) from both parents.
* Sickle Beta Thalassemia (HbSβ Thalassemia): This form occurs when an individual inherits one copy of the HbS gene and one copy of a mutated beta-globin gene.
* Other Variants: There are other less common forms of SCD, such as Sickle-Hemoglobin C Disease (HbSC) and various combinations of HbS with other abnormal hemoglobin variants.
	Painful episodes, often called sickle cell crises, happen when sickled cells block blood flow. Pain can be severe, can last for days or weeks, and often affects the limbs, back, chest or abdomen. Triggers can include dehydration, cold, stress and strenuous exercise, although a clear trigger is not always found.

The severity of SCD symptoms can vary among individuals, even within the same family. Factors such as the specific type of SCD and additional genetic variations contribute to this variability.
	People with sickle cell disease are more vulnerable to infections, especially in childhood. They may also have chronic anaemia because sickled red cells break down sooner than healthy red cells.

== Symptoms and Complications ==
The signs and symptoms of Sickle Cell Disease can range from mild to severe. Common symptoms include:
	== Complications ==
	Possible complications include acute chest syndrome, stroke, gallstones, leg ulcers, delayed growth, priapism, kidney problems, spleen problems, eye disease and severe anaemia after certain infections.

* Pain Crisis: Severe episodes of pain, known as pain crises or vaso-occlusive crises, occur when sickle-shaped red blood cells block blood flow, causing tissue damage and pain.
* Anemia: Sickle cells have a shorter lifespan than healthy red blood cells, leading to chronic anemia.
* Organ Damage: Sickle cells can block blood vessels, impairing blood flow to various organs and tissues, resulting in organ damage. Organs commonly affected include the spleen, lungs, kidneys, liver, and bones.
* Infections: Individuals with SCD are at an increased risk of infections, particularly bacterial infections, due to the functional impairment of the spleen.
* Stroke: The abnormal blood flow caused by sickle cells can lead to stroke, especially in children.
* Acute Chest Syndrome: A condition similar to pneumonia, characterized by chest pain, fever, and difficulty breathing.
	Acute chest syndrome is a serious lung complication that can cause fever, cough, chest pain and breathing difficulty. It normally requires urgent hospital treatment.

It is important for individuals with Sickle Cell Disease to receive regular medical care and monitoring to manage symptoms and prevent complications.
	== Diagnosis and Screening ==
	In the UK, babies are offered newborn blood spot screening for sickle cell disease. Diagnosis may also be made through blood tests such as haemoglobin analysis. Carrier screening and genetic counselling may be offered to people with a family history or higher inherited risk.

== Diagnosis ==
Sickle Cell Disease is typically diagnosed through newborn screening tests performed shortly after birth. These tests identify the presence of abnormal hemoglobin in the baby's blood. A confirmation of the diagnosis is usually done through specialized laboratory tests, such as hemoglobin electrophoresis, which can determine the specific type of SCD.
	Early diagnosis allows preventive care to begin before complications develop.

Genetic counseling and testing can also be beneficial for individuals with a family history of SCD or those planning to have children.
	== Treatment and Management ==
	Sickle cell disease usually needs lifelong care from a specialist team. Management may include a personal care plan, vaccinations, antibiotic prevention, folic acid where appropriate, pain plans and advice on avoiding triggers such as dehydration and cold exposure.

== Treatment ==
While there is no cure for Sickle Cell Disease, various treatments and interventions aim to manage symptoms, prevent complications, and improve quality of life. These may include:
	Hydroxycarbamide, also known as hydroxyurea, may be used to reduce painful crises. People taking it usually need regular blood tests because it can lower white blood cells and platelets.

* Pain Management: Pain crises are typically managed with analgesic medications, such as nonsteroidal anti-inflammatory drugs (NSAIDs) and opioid pain relievers.
* Hydroxyurea: This medication can increase the production of fetal hemoglobin, which reduces the occurrence of sickle cell crises.
* Blood Transfusions: Regular blood transfusions can help prevent complications and manage severe anemia.
* Bone Marrow Transplant: In certain cases, a bone marrow transplant may be considered as a potential curative treatment option.
* Infection Prevention: Vaccinations, antibiotic prophylaxis, and early treatment of infections are important to prevent complications.
* Supportive Care: Adequate hydration, nutritional support, and appropriate management of complications are essential for overall well-being.
	Blood transfusion or red cell exchange may be used for severe anaemia, stroke prevention, acute chest syndrome or other complications. People who receive many transfusions may need treatment to reduce excess iron.

Individualized treatment plans are developed in collaboration with healthcare providers, considering the specific needs and circumstances of each individual with Sickle Cell Disease.
	Stem cell or bone marrow transplant is a potential cure, but it carries significant risks and is usually considered only for selected patients. In 2025, NHS England announced access to exagamglogene autotemcel, a gene-editing treatment for eligible older children and adults with severe recurrent crises who meet specialist criteria.

== Research and Outlook ==
Ongoing research efforts aim to improve our understanding of Sickle Cell Disease and develop more effective treatments. Gene therapies, novel medications, and advancements in supportive care strategies provide hope for better outcomes and enhanced quality of life for individuals with SCD.
	== Living With Sickle Cell Disease ==
	Regular review is important even when symptoms are quiet. People may be advised to keep hydrated, avoid sudden cold exposure, manage fever promptly, keep vaccinations up to date and seek help quickly for severe pain, breathing difficulty, signs of infection, neurological symptoms or sudden worsening anaemia.

	The condition can affect school, work, travel, pain management, mental health and family life, so good care includes practical support as well as medical treatment.

== See Also ==	== See Also ==
	* [[Haemoglobin]]
	* [[Anaemia]]
	* [[Blood_Transfusion]]
	* [[Genetics]]

* [[Hemoglobin]] - Learn more about the protein responsible for carrying oxygen in red blood cells.
* [[Anemia]] - Explore a condition characterized by a decrease in the number of red blood cells or a deficiency in hemoglobin.
* [[Thalassemia]] - Discover a group of inherited blood disorders characterized by abnormal hemoglobin production.
* [[Bone Marrow Transplant]] - Understand a procedure that can provide a potential cure for certain individuals with Sickle Cell Disease.
	== References ==
	* [https://www.nhs.uk/conditions/sickle-cell-disease/symptoms/ NHS: Sickle cell disease symptoms]
	* [https://www.nhs.uk/conditions/sickle-cell-disease/treatment/ NHS: Sickle cell disease treatment]
	* [https://www.nhsinform.scot/illnesses-and-conditions/blood-and-lymph/sickle-cell-disease/ NHS inform: Sickle cell disease]
	* [https://www.england.nhs.uk/2025/01/revolutionary-gene-editing-therapy-for-sickle-cell/ NHS England: gene-editing therapy for sickle cell disease]

	[[Category:Medicine]]
	[[Category:Haematology]]
	[[Category:Genetics]]