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Prothrombin

Molecular Test Requisition | Specimen Information | Billing Information | Contact Us | CPT Codes | Print Page

Gene Symbol: F2

Chromosomal Locus: 11p11.2

Protein: Prothrombin

Pseudonyms: Coagulation Factor 2

TURNAROUND TIME: 5 business days 

TESTING METHODOLOGY: Detection of a point mutation of G>A at c.20210 by analysis on the Verigene system (FDA approved).

SPECIMEN REQUIREMENTS:

  • Collect: Prefer two 5ml whole blood EDTA (lavender top) tube.
  • Min. Collection: 0.7 ml whole blood EDTA.
  • Transport: blood EDTA at Room Temp shipped regular next day air (No Saturday delivery; store specimen at 4°C and ship Monday).
  • Stability: Ambient: up to 7 days; Refrigerated: 2 weeks. Frozen: unacceptable
  • Unacceptable Conditions: Serum. Frozen or severely hemolyzed blood. Clotted blood.
  • Prenatal testing: Direct: 5ml direct unspun amniotic fluid or 15mg CVS tissue with a backup flask growing. Culture: confluent T25 flask. Maternal blood sample is required for maternal cell contamination studies.

A Molecular Genetics Laboratory Test Requisition must accompany the specimen. Contact the Molecular Laboratory at 918-502-1721 to obtain further information.

Note:

Counseling and informed consent are recommended for genetic testing; Center for Genetic Testing at Saint Francis consent form is available as a resource but not required.

INTERPRETATIVE DATA:

Incidence: 1 in 1,000 people

Inheritance: Heterozygosity is inherited in an autosomal dominant manner and increases risk for VTEs (venous thromboembolims) 2- 5 fold. Homozygosity results in an increased risk but it is unclear how much more risk is gained from the second copy. Heterozygosity in combination with a FV mutation gives a 10-20 fold increased risk of VTE.

Disease Characteristics: Recurrent VTE (venous thromboembolism) especially DVT (deep vein thrombosis) in the legs and upper extremities. Also, possibly a risk of pregnancy loss and complications such as preeclampsia, intrauterine growth restriction, and placental abruption.

Related Tests: Factor V (FV), MTHFR

Clinical Sensitivity: 1-3% of patients presenting with a VTE (venous thromboembolism).

INDICATIONS FOR USE:

  • To determine the potential cause of unexplained or recurrent thrombosis in children or adults.
  • Patients undergoing surgery especially the potentially high-risk class of women taking estrogen supplements or smoking.
  • Evaluation of individuals before initiation of oral contraceptives.
  • Evaluation of women with recurrent pregnancy loss.

ADDITIONAL RESOURCES:

OMIM F2 Gene: - www.omim.org/entry/176930
OMIM Thrombophilia: - www.omim.org/entry/188050
Genetics Home Reference: www.ghr.nlm.nih.gov/condition/prothrombin-thrombophilia