Prothrombin Analysis

Prothrombin (Factor II) G20210A mutation is associated with elevated prothrombin levels. Individuals heterozygous for this mutation have an estimated 3-8 fold increased risk for venous thrombosis. The G20210A mutation has an overall prevalence of up to 3% in the Caucasian population, but it is rarely seen in other ethnic groups.

Analysis for the prothrombin G20210A mutation is offered as a specific DNA test, or as part of a thrombophilia panel (see Thrombosis panel) which also includes the factor V Leiden analysis. 8-14% of G20210A heterozygotes have other inherited thrombophilic disorders. Individuals with multiple thrombophilic mutations develop venous thromboembolism at a younger age and are at higher risk for recurrent thrombosis than those with a single defect.

Indications for Testing

• Personal history of two or more blood-clotting incidents
• Deep vein thrombosis
• Pulmonary embolism
• Family history of blood clots or prothrombin mutation
• Unexplained early-onset severe preeclampsia, placental abruption, or significant intrauterine growth retardation
• Recurrent unexplained first-trimester losses

Sample Requirements

3 – 4 mL whole blood in purple top EDTA tube

Sample Handling

Blood samples stored overnight should be refrigerated or kept cold. Blood samples should never be frozen. Specimens being sent from outside facilities should be packaged with a cold pack according to standard medical safety practices. The specimen should be shipped by overnight priority [scheduled to arrive by Friday morning at the latest].

Shipping Address

Center for Human Genetics Laboratory
10524 Euclid Avenue, Sixth Floor
Cleveland, OH 44106
216-983-1134

For local samples, please call Client Service (216-844-5227) to arrange for sample pick-up.

Turnaround Time

Three to nine days

CPT Code

81240

Please submit a completed Molecular Requisition for each sample.