Thrombotic Risk, Inherited Etiologies (Most Common) with Reflex to Factor V Leiden
Ordering Recommendation

Acceptable screening panel for common inherited thrombophilias.

Electromagnetic Clot Detection/Quantitative Enzymatic/Polymerase Chain Reaction/Fluorescence Monitoring
2-7 days
New York DOH Approval Status
This test is New York DOH approved.
Submit With Order
ARUP Consult®
Disease Topics
Specimen Required
Patient Preparation
Fasting preferred. Refer to Specimen Handling at for hemostasis/thrombosis specimen handling guidelines. 
Lt. blue (sodium citrate) AND lavender (EDTA) or pink (K2EDTA) AND serum separator tube or green (sodium or lithium heparin). 
Specimen Preparation
Serum Separator Tube or Green (sodium or lithium heparin) must be centrifuged and serum or plasma separated within 1 hour of collection. Transfer 1 mL centrifuged serum or plasma to ARUP Standard Transport Tube and label centrifuged tube for homocysteine testing. (Min: 0.5 mL) AND Transport two 2 mL aliquots platelet-poor plasma (sodium citrate) (Min: 1 mL/aliquot) AND Transport 5 mL whole blood (EDTA). (Min: 1 mL) 
Storage/Transport Temperature
Light blue (sodium citrate):  CRITICAL FROZEN. Separate specimens must be submitted when multiple tests are ordered.
Lavender whole blood and Serum or Green (sodium or lithium heparin): Refrigerated. 
Unacceptable Conditions
Specimens collected in any tube type not listed above. 
Light blue (sodium citrate): Ambient: Unacceptable; Refrigerated: Unacceptable; Frozen: 2 weeks
Lavender whole blood: Ambient: 2 hours; Refrigerated: 1 week; Frozen: Unacceptable
Serum or Green (sodium or lithium heparin):
Ambient: 1 hour; Refrigerated: 1 week; Frozen: 3 months 
Reference Interval
Effective November 18, 2013
Test Number
Reference Interval
0030235Partial Thromboplastin Time24-35 seconds
0030095Factor VIII, Activity
AgeReference Interval
0-6 years56-191%
7-9 years76-199%
10-11 years80-209%
12-13 years72-198%
14-15 years69-237%
16-17 years63-221%
18 years and older56-191%

0099869Homocysteine, TotalLess than 11 µmol/L, for both male and female
0056060Prothrombin (F2) c.*97G>A (G20210A) Pathogenic Variant
0030127APC Resistance Profile2.0 or greater
 Factor V Leiden by PCRNegative: The sample is negative for factor V Leiden, R506Q mutation.

Interpretive Data
Ratios less than 2.00 suggest APC resistance. This method uses factor V deficient plasma; therefore, APC resistance due to a nonfactor V mutation will not be detected. Extreme factor V deficiency may cause abnormal ratio. Elevated total homocysteine (tHcy) concentrations may be associated with vitamin B12 deficiency, folate deficiency, or inherited disorders of methionine metabolism. tHcy may also be used as a weak-graded risk factor for cardiovascular disease or stroke.

If APC resistance is normal, then no further testing will be added. If APC resistance is abnormally low, then Factor V Leiden by PCR will be added. Additional charges apply.  False elevations of plasma or serum homocysteine may occur if the plasma or serum is not promptly separated from the cells at the time of collection.
Hotline History
View Hotline History
CPT Code(s)
85730; 85240; 83090; 81240; 85307; if reflexed, add 81241
Component Test Code*Component Chart NameLOINC
0030052Thrombosis Interpretation48767-8
0030095Factor VIII, Activity3209-4
0030193APC Resistance13590-5
0030194Factor V Leiden by PCR21668-9
0030235Partial Thromboplastin Time14979-9
0056060Prothrombin (F2) G20210A Variant24475-6
0099869Homocysteine, Total13965-9
2001308FACV REF Specimen31208-2
2001334PT PCR Specimen31208-2
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
  • Activated Protein C Resistance
  • APC Resistance
  • APCR
  • F2 G20210A mutation
  • F8 Activity
  • Factor V Leiden
  • Factor V Leiden Functional Assay
  • Factor V Leiden PCR
  • Factor VIII, Activity
  • FVL
  • Hypercoag
  • Hypercoagulable Panel
  • Protein C Resistance
  • Prothrombin mutation
  • prothrombin time
  • PTT
  • total homocyteine