🎙️ Deep Dive: Hereditary Spherocytosis – Red Cell Breakdown Demystified 🩸🧬🧪
Welcome back to the Deep Dive series! Today, we’re cracking open a key haematology topic that crops up in the MSRA, paediatrics, and GP exams alike — Hereditary Spherocytosis (HS). Let’s get crystal clear on what makes red blood cells turn from flexible discs to fragile spheres — and why it matters. 🧠✨
🔍 What you’ll learn in this episode:
✅ Definition
→ HS is a genetic haemolytic anaemia due to red blood cell membrane protein defects (think: ankyrin, spectrin, band 3, protein 4.2).
→ It causes spherical, less flexible red cells that get destroyed in the spleen = chronic haemolysis 🔁
✅ Inheritance
→ Mostly autosomal dominant (~75%)
→ Also can be autosomal recessive or from de novo mutations 🧬
→ Strong link with family history 👨👩👦
✅ Pathophysiology
→ Cytoskeletal defects = loss of surface area
→ Red cells become spherocytes 🏀
→ Increased fragility, get trapped and destroyed in the spleen → anaemia
→ ↑ MCHC due to dehydration of spherocytes
→ Think: spleen = the villain & the victim 🦠
✅ Clinical Features
→ Classic triad: Anaemia, Jaundice, Splenomegaly
→ Gallstones from chronic haemolysis
→ Failure to thrive in children
→ Risk of aplastic crisis from Parvovirus B19
→ Mnemonic: “JOGGS OF FAILURE” – Jaundice, Organomegaly (spleen), Gallstones, Growth delay, Spherocytes
✅ Differentials
→ Autoimmune haemolytic anaemia (AIHA)
→ Key distinction: Direct Coombs test is negative in HS, positive in AIHA ✅
→ Also consider: transfusion reactions, liver disease, burns, hereditary stomatocytosis, ABO incompatibility in neonates 🧾
✅ Epidemiology
→ Prevalence: ~1 in 2000–5000
→ Most common hereditary haemolytic anaemia in people of Northern European descent 🌍
✅ Investigations
→ Blood film: spherocytes + polychromasia
→ FBC: anaemia, ↑ MCHC
→ Reticulocyte count: elevated
→ Unconjugated bilirubin, LDH↑, Haptoglobin↓
→ Direct Coombs: negative
→ Specialised tests: Osmotic gradient ektacytometry, membrane protein electrophoresis, genetic testing
→ Mnemonic: PHIL RED = Peripheral film, Haptoglobin, Iron studies, LDH/LFTs, Retic count, Ektacytometry, Direct Coombs
✅ Management
→ Folic acid 💊 – for high red cell turnover
→ Transfusions – if severe or during aplastic crisis
→ Splenectomy – for moderate to severe disease (curative)
→ Vaccinations + lifelong penicillin if splenectomy is done
→ Be cautious: Don’t splenectomise if diagnosis is unclear or if there's co-existing hereditary stomatocytosis
✅ Complications
→ Gallstones (bilirubin-based) – may need cholecystectomy
→ Aplastic crisis – parvovirus B19 🦠
→ Hemolytic crises, megaloblastic crisis (if folate deficient), splenic sequestration
→ Post-splenectomy sepsis – hence the vaccine and antibiotic need!
✅ Prognosis
→ Generally excellent with supportive care and splenectomy
→ Most live normal, healthy lives 💪
→ A minority may remain transfusion-dependent
📚 Your MSRA Revision Toolbox for HS:
📝 Revision Notes:
https://www.passthemsra.com/topic/hereditary-spherocytosis-revision-notes/
🃏 Flashcards:
https://www.passthemsra.com/topic/hereditary-spherocytosis-flashcards/
📖 Accordion Q&A Notes:
https://www.passthemsra.com/topic/hereditary-spherocytosis-accordion-qa-notes/
🧠 Rapid Quiz:
https://www.passthemsra.com/topic/hereditary-spherocytosis-rapid-quiz/
🧪 Quiz Link:
https://www.passthemsra.com/quizzes/hereditary-spherocytosis/
📌 Key Takeaway:
Hereditary Spherocytosis = fragile red cells, filtered by the spleen, fixed with folate and sometimes a splenectomy.
Spot the spherocytes, rule out AIHA, manage wisely — and don't forget your vaccines post-splenectomy!
#MSRA #HaematologyMSRA #HereditarySpherocytosis #MSRARevision #MSRAFlashcards #MedicalEducation #HaemolyticAnaemia #Spherocytes #PassTheMSRA #ParvovirusCrisis #SplenectomyGuidelines #FolicAcid #JOGGSofFailure
