Performed

Monday - Friday

Methodology

Real-Time Polymerase Chain Reaction

Reported

Routine: 12 - 14 days

Synonyms

  • Prothrombin Mutation
  • Factor II Mutation
  • Factor 2 Mutation
  • G20210A Mutation
  • G20210A Variant
  • Clinical Genomics

Performing Lab

Clinical Genomics

Turnaround Time

14 days

Add-on Eligibility

Yes, within 7 days of collection
*If DNA has been extracted previously for other Clinical Genomics tests, this is stored for 6 weeks and may qualify for add-on

Specimen Type

Blood

Specimen Volume

5 mL (Minimum: 1 mL)

Collection Container

EDTA Whole Blood Tube (Lavender Top Vacutainer)

Unacceptable Conditions

  1. Severely clotted or grossly hemolyzed specimens
  2. Specimens that have been improperly collected, stored, or transported
  • Specimens collected in preservatives other than EDTA
    • ACD tubes are accepted, but EDTA is preferred
  • Serum or plasma
  • Specimens that have been frozen
  • Commingled specimens
  1. Specimens in tubes that have been damaged or broken during transport
  2. Specimens with insufficient volume for testing
  3. Unlabeled or mislabeled specimens

Storage/Transport Temperature

Transport Instructions      
Collection Location Transport Temperature Processing Required Timeframe
ED/Inpatient Room Temperature None Specimen must be received by the lab within 3 days of collection
Laboratory/Outpatient/Off-Site Room Temperature None Specimen must be received by the lab within 3 days of collection

Storage: Refrigerated

Stability (from collection to initiation)

Stability:
Prior to Extraction:
  • Room Temperature: 3 days
  • Refrigerated: 7 days
  • Frozen: Unacceptable
Extracted DNA:
  • Room Temperature: Unacceptable
  • Refrigerated: Unacceptable
  • Frozen: Indefinitely

Laboratory Storage: 
  • Original Specimen: Refrigerated
  • Extracted DNA: Frozen
Laboratory Retention: 
  • Original Specimen: 6 weeks
  • Extracted DNA: 6 weeks

Collection Instructions

Labeling Instructions:
When labeling blood tubes, leave a small window visible for the lab to assess the fill volume and sample integrity. Ensure that the barcode is in the correct orientation.


Collection Instructions:
Follow the correct order of draw when collecting with additional orders and tube types:
     

Reference Interval

Not Detected: Negative for the Factor II, prothrombin G20210A mutation

Interpretive Data

The Factor II, G20210A mutation is a common genetic risk factor for venous thrombosis associated with elevated prothrombin levels leading to increased rates of thrombin generation and excessive growth of fibrin clots. The prothrombin (F2) c.*97G>A sequence variant (historically known as 20210G>A) is the second most common cause of inherited thrombophilia. Heterozygosity for the F2 c.*97G>A variant is found in 0.3 to 3% of the general population depending on ethnicity, 6% of individuals with first venous thromboembolism (VTE), and 18 to 21% of individuals with a personal or family history of recurrent VTE. 

The expression of Factor II thrombophilia is impacted by coexisting genetic thrombophilic disorders, acquired thrombophilic disorders (eg, malignancy, hyperhomocysteinemia, high factor VIII levels), and circumstances including: pregnancy, oral contraceptive use, hormone replacement therapy, selective estrogen receptor modulators, travel, central venous catheters, surgery, and organ transplantation.

Incidence: 
Heterozygosity occurs in:
  • Caucasians: 1 - 3% 
  • Hispanics: 1% 
  • African Americans: 0.3%
Homozygosity is very rare; < 1 in 10,000 individuals

Inheritance: Autosomal dominant with incomplete penetrance

Penetrance: The risk of venous thromboembolism is increased 2-4 fold for heterozygotes and presumed to be higher for homozygotes.

Cause: Homozygosity or heterozygosity for F2 c.20210G>A (G20210A)

Mutation Tested: F2 c.20210G>A (G20210A)

Clinical Sensitivity for Venous Thrombosis: ~10%

Methodology: Polymerase chain reaction and fluorescence monitoring

Analytical Sensitivity and Specificity: 99%

Limitations: Rare diagnostic errors can occur due to primer site mutations. F2 gene mutations, other than G20210A, will not be detected.

This test was developed and its performance characteristics determined by the UC San Diego Health System Molecular Diagnostics Laboratory. It has not been cleared or approved by the US Food and Drug Administration. FDA clearance or approval is not required for clinical use. The result of this test should be interpreted using all relevant clinical data and should not be used alone for clinical diagnosis or patient management decisions. 
Ordering

Performed

Monday - Friday

Methodology

Real-Time Polymerase Chain Reaction

Reported

Routine: 12 - 14 days

Synonyms

  • Prothrombin Mutation
  • Factor II Mutation
  • Factor 2 Mutation
  • G20210A Mutation
  • G20210A Variant
  • Clinical Genomics

Performing Lab

Clinical Genomics

Turnaround Time

14 days

Add-on Eligibility

Yes, within 7 days of collection
*If DNA has been extracted previously for other Clinical Genomics tests, this is stored for 6 weeks and may qualify for add-on
Collection

Specimen Type

Blood

Specimen Volume

5 mL (Minimum: 1 mL)

Collection Container

EDTA Whole Blood Tube (Lavender Top Vacutainer)

Unacceptable Conditions

  1. Severely clotted or grossly hemolyzed specimens
  2. Specimens that have been improperly collected, stored, or transported
  • Specimens collected in preservatives other than EDTA
    • ACD tubes are accepted, but EDTA is preferred
  • Serum or plasma
  • Specimens that have been frozen
  • Commingled specimens
  1. Specimens in tubes that have been damaged or broken during transport
  2. Specimens with insufficient volume for testing
  3. Unlabeled or mislabeled specimens

Storage/Transport Temperature

Transport Instructions      
Collection Location Transport Temperature Processing Required Timeframe
ED/Inpatient Room Temperature None Specimen must be received by the lab within 3 days of collection
Laboratory/Outpatient/Off-Site Room Temperature None Specimen must be received by the lab within 3 days of collection

Storage: Refrigerated

Stability (from collection to initiation)

Stability:
Prior to Extraction:
  • Room Temperature: 3 days
  • Refrigerated: 7 days
  • Frozen: Unacceptable
Extracted DNA:
  • Room Temperature: Unacceptable
  • Refrigerated: Unacceptable
  • Frozen: Indefinitely

Laboratory Storage: 
  • Original Specimen: Refrigerated
  • Extracted DNA: Frozen
Laboratory Retention: 
  • Original Specimen: 6 weeks
  • Extracted DNA: 6 weeks

Collection Instructions

Labeling Instructions:
When labeling blood tubes, leave a small window visible for the lab to assess the fill volume and sample integrity. Ensure that the barcode is in the correct orientation.


Collection Instructions:
Follow the correct order of draw when collecting with additional orders and tube types:
     
Result Interpretation

Reference Interval

Not Detected: Negative for the Factor II, prothrombin G20210A mutation

Interpretive Data

The Factor II, G20210A mutation is a common genetic risk factor for venous thrombosis associated with elevated prothrombin levels leading to increased rates of thrombin generation and excessive growth of fibrin clots. The prothrombin (F2) c.*97G>A sequence variant (historically known as 20210G>A) is the second most common cause of inherited thrombophilia. Heterozygosity for the F2 c.*97G>A variant is found in 0.3 to 3% of the general population depending on ethnicity, 6% of individuals with first venous thromboembolism (VTE), and 18 to 21% of individuals with a personal or family history of recurrent VTE. 

The expression of Factor II thrombophilia is impacted by coexisting genetic thrombophilic disorders, acquired thrombophilic disorders (eg, malignancy, hyperhomocysteinemia, high factor VIII levels), and circumstances including: pregnancy, oral contraceptive use, hormone replacement therapy, selective estrogen receptor modulators, travel, central venous catheters, surgery, and organ transplantation.

Incidence: 
Heterozygosity occurs in:
  • Caucasians: 1 - 3% 
  • Hispanics: 1% 
  • African Americans: 0.3%
Homozygosity is very rare; < 1 in 10,000 individuals

Inheritance: Autosomal dominant with incomplete penetrance

Penetrance: The risk of venous thromboembolism is increased 2-4 fold for heterozygotes and presumed to be higher for homozygotes.

Cause: Homozygosity or heterozygosity for F2 c.20210G>A (G20210A)

Mutation Tested: F2 c.20210G>A (G20210A)

Clinical Sensitivity for Venous Thrombosis: ~10%

Methodology: Polymerase chain reaction and fluorescence monitoring

Analytical Sensitivity and Specificity: 99%

Limitations: Rare diagnostic errors can occur due to primer site mutations. F2 gene mutations, other than G20210A, will not be detected.

This test was developed and its performance characteristics determined by the UC San Diego Health System Molecular Diagnostics Laboratory. It has not been cleared or approved by the US Food and Drug Administration. FDA clearance or approval is not required for clinical use. The result of this test should be interpreted using all relevant clinical data and should not be used alone for clinical diagnosis or patient management decisions. 

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