Sickle Cell Anaemia (Sickle Cell Disease - SCD)

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Recently, the President of India reaffirmed the country's commitment to eliminating Sickle Cell Anaemia before the national target of 2047. The announcement strengthens the Government's resolve under the National Sickle Cell Anaemia Elimination Mission, which seeks to reduce the disease burden through early screening, timely diagnosis, genetic counselling, and comprehensive healthcare, particularly among tribal populations, where the disease is most prevalent.

Introduction

Sickle Cell Anaemia (SCA), also known as Sickle Cell Disease (SCD), is an inherited genetic blood disorder that affects haemoglobin, the oxygen-carrying protein present in red blood cells (RBCs). Because of an abnormal form of haemoglobin called Haemoglobin S (HbS), red blood cells lose their normal flexible shape and become rigid, sickle-shaped (crescent-shaped). These abnormal cells obstruct blood flow, reduce oxygen delivery to tissues, and cause repeated episodes of pain, anaemia, infections, and damage to vital organs.

How Sickle Cell Anaemia Affects Blood Flow

• Under normal conditions, red blood cells are disc-shaped, flexible, and elastic, enabling them to move smoothly through even the smallest blood vessels and efficiently transport oxygen throughout the body.

• In individuals with Sickle Cell Disease, the presence of Haemoglobin S causes red blood cells to become hard, sticky, and sickle-shaped, especially under conditions such as low oxygen levels, dehydration, infection, or physical stress.

• These sickle-shaped cells cannot bend easily and frequently become trapped inside narrow blood vessels. The resulting blockage reduces or completely stops blood circulation to different organs, leading to severe pain, tissue damage, and repeated episodes of vaso-occlusive crises. Their shortened lifespan also causes chronic anaemia, as sickled red blood cells survive only about 10–20 days, compared to 120 days for normal red blood cells.

Cause of Sickle Cell Anaemia

• Sickle Cell Anaemia is caused by a mutation in the HBB gene, which provides instructions for producing the beta-globin protein, a major component of haemoglobin.

• The disease follows an autosomal recessive pattern of inheritance, meaning that a child develops the disease only when both parents pass on the defective sickle-cell gene.

• Individuals inheriting one normal gene and one defective gene are said to have the Sickle Cell Trait (SCT). Although such individuals generally remain healthy and show no major symptoms, they can transmit the abnormal gene to their offspring.

   

Signs and Symptoms

• The symptoms of Sickle Cell Disease generally begin during early childhood, usually after six months of age when fetal haemoglobin is replaced by adult haemoglobin.

• In the early stages, affected children commonly experience severe anaemia, persistent tiredness, swelling of the hands and feet (dactylitis), irritability, delayed growth, and jaundice due to rapid destruction of red blood cells.

• As the disease progresses, patients suffer from recurrent episodes of severe pain, repeated infections, delayed physical development, damage to organs such as the brain, kidneys, lungs, spleen, liver, and heart, vision problems, and an increased risk of stroke.

Diagnosis

• Early diagnosis plays a crucial role in preventing complications.

• Diagnosis is primarily carried out through newborn screening, blood tests, haemoglobin electrophoresis, High-Performance Liquid Chromatography (HPLC), and genetic testing, which help identify the presence of abnormal haemoglobin.

• Screening programmes are especially important in regions where the disease is highly prevalent.

Treatment and Management

• Although Sickle Cell Disease is a lifelong condition, appropriate medical care can significantly improve both quality of life and life expectancy.

• Treatment mainly focuses on pain management, prevention of infections through vaccination and antibiotics, blood transfusions to manage severe anaemia, adequate hydration, nutritional support, and medicines such as Hydroxyurea, which increases fetal haemoglobin levels and reduces painful crises.

• A Bone Marrow Transplant (Stem Cell Transplant) currently remains the only established curative treatment, although it is suitable for only a limited number of patients with compatible donors.

Distribution in India

• India has the second-highest burden of Sickle Cell Disease in the world, after Africa.

• The disease is particularly prevalent among Scheduled Tribes (STs) and certain Scheduled Castes (SCs) and Other Backward Classes (OBCs) living in central, western, and southern India.

• High-prevalence states include Madhya Pradesh, Maharashtra, Chhattisgarh, Gujarat, Odisha, Jharkhand, Rajasthan, Telangana, Andhra Pradesh, Karnataka, and parts of Uttar Pradesh.

National Sickle Cell Anaemia Elimination Mission (2023)

• The National Sickle Cell Anaemia Elimination Mission was launched by the Government of India in July 2023 with the ambitious objective of eliminating Sickle Cell Disease as a public health problem by 2047.

• The mission seeks to screen nearly seven crore individuals aged 0–40 years in affected tribal regions, provide universal access to diagnosis and treatment, strengthen healthcare infrastructure, promote genetic counselling, create public awareness, and establish a comprehensive digital registry of patients.

• It is implemented through the combined efforts of the Ministry of Health and Family Welfare, the Ministry of Tribal Affairs, state governments, and various healthcare institutions.

Importance of Eliminating Sickle Cell Disease

Eliminating Sickle Cell Disease will substantially reduce child mortality, improve maternal and child health, lower healthcare expenditure, and enhance the quality of life of millions of vulnerable individuals.

The programme also contributes to achieving Universal Health Coverage, improving tribal health outcomes, reducing social inequalities, and advancing the objectives of Sustainable Development Goal (SDG) 3 relating to Good Health and Well-being.

Challenges

Despite significant policy initiatives, several challenges continue to hinder effective disease control.

Limited awareness, delayed diagnosis, inadequate access to specialised healthcare facilities in remote tribal regions, shortage of trained healthcare personnel, social stigma, poor genetic counselling services, and the high cost of advanced therapies such as bone marrow transplantation and gene therapy remain major obstacles.

UPSC Prelims Facts

Sickle Cell Anaemia is an autosomal recessive inherited blood disorder caused by a mutation in the HBB gene, resulting in the production of Haemoglobin S (HbS). It causes crescent-shaped red blood cells, chronic anaemia, painful vaso-occlusive crises, and organ damage. Individuals with one defective gene have the Sickle Cell Trait and usually remain asymptomatic. Bone marrow transplantation is the only established cure, while gene therapy is an emerging treatment. India launched the National Sickle Cell Anaemia Elimination Mission (2023) with the target of eliminating the disease as a public health problem by 2047, focusing particularly on tribal populations.

Conclusion

Sickle Cell Anaemia remains one of India's most significant genetic public health challenges, particularly among vulnerable tribal communities. While advances in screening, diagnosis, treatment, and gene therapy offer new hope, achieving elimination requires sustained political commitment, strong healthcare systems, community awareness, and widespread genetic counselling.