Haem: Factor V Leiden: Free MSRA Podcast

🎙️ Deep Dive: Factor V Leiden – The Sticky Switch of Clotting 🩸🧬🛑Welcome to another fast-paced revision episode, perfect for MSRA prep and clinical understanding! Today, we’re diving into Factor V Leiden, the most common inherited thrombophilia — the genetic twist that makes blood just a bit too eager to clot. 🧠💥🔍 What you’ll learn in this episode:✅ Definition→ Factor V Leiden is a genetic mutation in the F5 gene, making clotting factor V resistant to inactivation by activated protein C (APC).→ Leads to a hypercoagulable state, increasing the risk of venous thromboembolism (VTE).✅ Genetics→ Autosomal dominant inheritance 🧬→ Only one copy needed to increase clot risk (heterozygous = 3–5x risk)→ Homozygous carriers have up to 8x or higher risk✅ Pathophysiology→ Normally, APC inactivates factor V to regulate clotting→ In Factor V Leiden, this “off switch” doesn’t work well – “sticky switch” analogy→ Results in prolonged thrombin generation, more fibrin = increased clot risk✅ Symptoms & Presentation→ Many are asymptomatic!→ If symptomatic: classic DVT (leg swelling, pain, redness) or PE (SOB, chest pain, haemoptysis)→ May also be found after recurrent miscarriage or unprovoked clots in young patients✅ Differentials→ Other inherited thrombophilias:Protein C deficiencyProtein S deficiencyAntithrombin deficiencyProthrombin G20210A mutation→ Plus acquired risks: immobility, surgery, pregnancy, HRT, malignancy, autoimmune disease✅ Epidemiology→ Present in ~5% of UK Caucasians→ Rare in Black African, East Asian, Indigenous Australian, Native American populations→ May have had evolutionary benefits (e.g. reduced postpartum bleeding) 🧬🤔✅ Investigations→ Activated Protein C resistance assay (initial screen)→ DNA testing for F5 mutation (gold standard)→ Clot imaging if acute DVT/PE suspected:Doppler ultrasoundCT Pulmonary Angiography (CTPA)✅ Management→ If clot occurs: treat with DOACs or warfarin, duration depends on whether it was provoked→ If no clot: usually no routine anticoagulation→ Focus on lifestyle: stay active, healthy weight, avoid long immobility 🧘‍♂️→ Temporary prophylaxis (e.g. LMWH) in high-risk situations like surgery, pregnancy→ Caution with oestrogen-based contraception 💊→ Pregnancy care: LMWH may be used if high-risk or previous VTE✅ Complications→ Recurrent VTE (DVT/PE)→ Bleeding risks from anticoagulants→ Risk increases during surgery, immobility, and pregnancy→ Complex links to recurrent miscarriage, possibly related to placental clotting✅ Interesting Twist 🤯→ Some potential protective effects:Less menstrual bleedingLower risk of intracranial haemorrhagePossible improved outcomes in sepsis or ARDS→ A classic example of a genetic paradox📚 Your MSRA Revision Toolkit for Factor V Leiden:📝 Revision Notes:https://www.passthemsra.com/topic/factor-v-leiden-deficiency-revision-notes/🃏 Flashcards:https://www.passthemsra.com/topic/factor-v-leiden-deficiency-flashcards/📖 Accordion Q&A Notes:https://www.passthemsra.com/topic/factor-v-leiden-deficiency-accordion-qa-notes/🧠 Rapid Quiz:https://www.passthemsra.com/topic/factor-v-leiden-deficiency-rapid-quiz/🧪 Quiz Link:https://www.passthemsra.com/quizzes/factor-v-leiden/📌 Key Takeaway🧬 Factor V Leiden = sticky clotting switch🔎 Think: inherited, asymptomatic or VTE presentations, diagnosed by APC resistance + DNA testing💊 Manage based on clot risk, not just gene carriage🧠 Remember the “sticky switch” analogy – and keep this high-yield thrombophilia firmly in mind for MSRA!#MSRA #FactorVLeiden #Thrombophilia #MSRARevision #MSRAFlashcards #VTE #HaematologyMSRA #ClottingDisorders #PassTheMSRA #Haematology #VenousThromboembolism #StickySwitch