🏥 Stations

🧠 Qbank

📖 Book

😃 More

💳 Pricing

🔒 Dashboard

📖 OSCE Learning

🔒 OSCE Stations

🔒 Qbank

🔐 Membership
Share your insights

Help us by sharing what content you've recieved in your exams


Haemoglobinopathies

Specialties > Emergency medicine and intensive care

Background knowledge 🧠

Definition

  • Haemoglobinopathies are inherited disorders affecting the structure or production of haemoglobin.
  • Includes conditions such as sickle cell disease and thalassaemias.
  • Results in abnormal oxygen transport and red cell destruction.

Epidemiology

  • Common in areas with high malaria prevalence (e.g., sub-Saharan Africa, Mediterranean, South Asia).
  • Sickle cell disease: approximately 12,000-15,000 people in the UK affected.
  • Thalassaemia: more common in people of Mediterranean, Middle Eastern, or Asian descent.

Aetiology and Pathophysiology

  • Sickle cell disease: mutation in the HBB gene leading to HbS production.
  • Thalassaemia: gene deletions or mutations leading to reduced or absent synthesis of alpha or beta globin chains.
  • Leads to haemolysis, anaemia, and in sickle cell, vaso-occlusive crises.
  • Severity depends on specific genetic mutation and zygosity.

Types

  • Sickle cell disease: HbSS (most common), HbSC, HbS-beta thalassaemia.
  • Thalassaemia: Alpha thalassaemia (1-4 gene deletions), Beta thalassaemia (minor, intermedia, major).
  • Other haemoglobinopathies: HbE, HbD, HbC.

Clinical Features 🌡️

Symptoms

  • Anaemia: fatigue, pallor, dyspnoea.
  • Sickle cell: pain crises, dactylitis in infants, chest pain, fever.
  • Thalassaemia: symptoms of anaemia, growth retardation in children, skeletal deformities.
  • Jaundice due to haemolysis.
  • Splenomegaly (more common in thalassaemia).

Signs

  • Pallor, jaundice, and scleral icterus.
  • Splenomegaly in thalassaemia.
  • Delayed puberty or growth in children with severe forms.
  • Characteristic facies (frontal bossing) in thalassaemia major.
  • Leg ulcers (more common in sickle cell disease).

Investigations 🧪

Tests

  • Full blood count (FBC): anaemia, microcytosis in thalassaemia, normocytic anaemia in sickle cell.
  • Blood film: target cells in thalassaemia, sickle cells in sickle cell disease.
  • Haemoglobin electrophoresis: confirms diagnosis and identifies haemoglobin variants.
  • Genetic testing: for definitive diagnosis.
  • Iron studies: to differentiate between iron deficiency and thalassaemia.
  • Prenatal testing: chorionic villus sampling or amniocentesis for at-risk pregnancies.

Management 🥼

Management

  • Sickle cell: Hydroxycarbamide to reduce crises, blood transfusions for severe anaemia.
  • Thalassaemia major: Regular blood transfusions, iron chelation therapy to prevent iron overload.
  • Bone marrow transplant: potential cure, especially in children.
  • Folic acid supplementation to support erythropoiesis.
  • Pain management in sickle cell crises: NSAIDs, opioids.
  • Vaccinations: prevent infections in asplenic patients.
  • Genetic counselling for affected families.

Complications

  • Infections: particularly in asplenic patients (e.g., pneumococcal infections).
  • Iron overload in thalassaemia due to transfusions.
  • Stroke: particularly in sickle cell disease.
  • Chronic organ damage: kidneys, liver, lungs (more common in sickle cell disease).
  • Gallstones: due to chronic haemolysis.
  • Leg ulcers and avascular necrosis (sickle cell disease).

Prognosis

  • Life expectancy reduced in sickle cell disease, especially with complications.
  • Thalassaemia major: improved outcomes with regular treatment, but still significant morbidity.
  • Prognosis improving with better management and early diagnosis.
  • Bone marrow transplant offers potential cure for some patients.
  • Ongoing research into gene therapy as a potential treatment.

Key Points

  • Inherited disorders with significant morbidity and mortality.
  • Early diagnosis and management are key to improving outcomes.
  • Hydroxycarbamide and transfusions are mainstays of treatment.
  • Bone marrow transplant can be curative.
  • Prophylactic measures (e.g., vaccinations) essential to prevent complications.

No comments yet 😉

Leave a Reply

Emergency medicine and intensive care