Home Test Search Results Factor VIII (8) Gene Sequencing and Inversions Assay
Factor VIII (8) Gene Sequencing and Inversions Assay


The type of mutation correlates with disease severity and likelihood of inhibitor formation. Mutation detection can confirm the diagnosis when the traditional lab workup is muddied by complicating factors like inflammation, stress, infection, hormone replacement therapy, age, acute phase response, menstrual cycle, pregnancy, exercise, ABO blood type, or lupus anticoagulant. Confirming carrier status can inform family planning decisions.

STAT: < 48 hours (M-F)

NGS, Inversion Assay

Draw Tube: Purple Top

Sample Type: EDTA Whole Blood


Specimen Requirements

Sample Type Volume Required Minimum Volume Stability
PREFERRED EDTA Whole Blood 3mL 1mL Room Temp.: 1 month
Refrigerated: 1 month
Frozen (-20C): 2 weeks
Frozen (-80C): 6 months
ALTERNATIVE Cheek swab 2 swab - Room Temp.: 1 month
Refrigerated: 1 month
REJECTION CRITERIA Sample contamination; sample compromised

General Information

METHODOLOGY NGS, Inversion Assay
STAT TAT < 48 hours (M-F)
STAT TAT Performance > 90% of results released in 48 hours
ROUTINE TAT < 5 days (M-F)
ALTERNATIVE NAMES Factor 8, F8, Factor VIII, FVIII, Hemophilia A
DESCRIPTION This test sequences the exons plus 5bp of the flanking introns of F8, plus deep intronic and promoter mutations that have been associated with disease. Additionally, this test looks specifically for the intron 1 and intron 22 inversions using custom PCR assays, which cause ~50% of severe hemophilia A cases. Sanger sequencing may be used to confirm variants as needed. Hemophilia A has a prevalence of 1:5000 (males).
LIMITATIONS This test will not detect variants located outside of the targeted DNA regions. This test is not optimized to detect chimerism or somatic mosaicism. This test will detect small indels but may miss larger deletions or duplications. Balanced structural variants will not be detected unless specifically targeted by a custom PCR assay.
NORMAL RANGE Interpretation: Negative

1.) Santagostino E and Fasulo MR. Semin Thromb Hemost 2013;39(7):697-701;
2.) Aledort LM, Coates J. Am J Hematol. 2005 Jun;79(2):172-3.
3.) Lillicrap D and James, P. World Federation of Hemophilia 2009; No. 47.

SAMPLE REPORT Upon request

Test Codes

CPT CODE 81406, 81407
LOINC CODE 94234-2