Name
PROTHROMBIN 20210 (MUTATION)
DESCRIPTION
DETAIL
CAUSES Replacement of G for A in the 3β untranslated region of the prothrombin gene -------------------------------------------------------------------------- DIFFERENTIAL DIAGNOSIS β’ Factor V Leiden β’ Protein S deficiency β’ Antithrombin deficiency β’ Dysfi brinogenemia β’ Dysplasminogenemia β’ Homocysteinemia β’ Protein C deficiency β’ Elevated factor VIII levelsLABORATORY β’ DNA analysis for mutation. β’ Although prothrombin levels are elevated, this is not a sensitive test to make the diagnosis.
TYPENOTES
RISK FACTORS: Oral contraceptives, pregnancy & use of HRT increase risk of venous thrombosis.GENERAL MEASURES β’ Routine anticoagulation for asymptomatic patients with prothrombin 20210 is not recommended β’ Patients with prothrombin 20210 and a first thrombosis should be anticoagulated β’ The role of family screening for prothrombin 20210 is unclear since most patients with this mutation do not have thrombosis. Screening should be considered for woman considering using oral contraceptives or pregnancy with a family history of prothrombin 20210. ACTIVITY No restrictions DIET No restrictions PATIENT EDUCATION Patients should be educated about use of oral anticoagulant therapy if taking such. Avoid NSAIDs while on warfarin. DRUG(S) OF CHOICE . Low molecular weight heparin (LMWH) . Enoxaparin (Lovenox). 1 mg/kg SQ bid. Alternatively, 1.5 mg/kg SQ per day. Initially for at least 5 days or until INR is 2-3 at which time it can be stopped. . Tinzaparin (Innohep). 175 anti-Xa IU/kg SQ q/day . Dalteparin (Fragmin). 200 IU/kg q/day . Oral anticoagulant - warfarin (Coumadin) 5 mg po q/day initially and adjusted to INR of 2-3. Patients should be maintained on warfarin for at least 6 months. Contraindications: Active bleeding precludes anticoagulation; risk of bleeding is a relative contraindication to long-term anticoagulation Precautions: . Observe patient for signs of embolization, further thrombosis, or bleeding . Avoid IM injections . Periodically check stool and urine for occult blood, monitor complete blood counts including platelets ALTERNATIVE DRUGS Heparin 80 mg/kg IV bolus followed by 18 mg/kg/hr. Adjust dose depending on PTT. . Heparin - thrombocytopenia and/or paradoxical thrombosis with thrombocytopenia PATIENT MONITORING Warfarin requires periodic (monthly after initial stabilization) monitoring of the INR PREVENTION/AVOIDANCE Patients with prothrombin 20210 without thrombosis do not require prophylactic treatment POSSIBLE COMPLICATIONS Recurrent thrombosis (requires indefi nite anticoagulation) EXPECTED COURSE/PROGNOSIS When compared to normal individuals, persons with prothrombin 20210 have normal life spans . LMWH - adjust dose in renal insufficiency
RELATED DISEASE
Not Available Disease
DISEASE
INVESTIGATION
PROTHROMBIN TIME, COMPLETE BLOOD COUNT