OSCE — Inherited Thrombophilia (Factor V Leiden & Protein C/S Deficiency) · MBBS OSCE

Brief (to candidate)

You will assess a patient with a presentation consistent with Inherited Thrombophilia (Factor V Leiden & Protein C/S Deficiency).
You have 8 minutes to take a focused history, outline examination, investigations, and management including red flags.

Clinical context

Inherited thrombophilias are genetic disorders increasing the risk of venous thromboembolism (VTE). The commonest are factor V Leiden (activated protein C resistance; the single commonest inherited thrombophilia in Europeans, autosomal dominant, carrier rate 3 to 8 percent) and the prothrombin G20210A mutation (raised prothrombin; 2 percent of Europeans). Less common but higher-risk are deficiencies of the natural anticoagulants — antithrombin, protein C, protein S — which cause more severe, younger-onset, unusual-site thrombosis and warfarin-induced skin necrosis (protein C/S). Hyperhomocysteinaemia (MTHFR mutations) raises both venous and arterial thrombosis risk. Indications to test: VTE

Candidate tasks

Clarify onset, severity, associated features, and red-flag symptoms.
State focused examination priorities.
List first-line investigations and any named score/criteria.
Give immediate resuscitation steps.
Outline definitive management with doses/routes where standard.
Name complications and disposition (ward / HDU / theatre / discharge safety-net).
Mention one special-population modifier (pregnancy, child, elderly, CKD).

Examiner checklist

Domain	Pass behaviours
Definition	Correct working diagnosis language
Assessment	Focused, prioritised, red flags sought
Investigations	Appropriate first-line + interpretation
Emergency care	ABC / time-critical actions first
Definitive care	Specific drugs/procedures, not generic phrases
Safety	Unprovoked VTE under 50 years or in unusual sites (cerebral, mesenteric, portal)
Safety	Warfarin-induced skin necrosis early in treatment — protein C or S deficiency; s
Safety	Recurrent VTE despite anticoagulation or strong family history — antithrombin de
Communication	Clear plan and safety-netting

Model outline

Lead with the working diagnosis and life threats. Resuscitate before definitive tests when unstable. Use guideline-standard therapy with named agents and doses. Document escalation criteria and follow-up. A safe candidate is specific, structured, and never delays critical care for non-urgent imaging.