Ordering Recommendation

Identify causal F8 variant in individuals with established mild to moderate hemophilia A and determine carrier status for those with a family history of mild to moderate hemophilia A. For severe hemophilia A,  Hemophilia A (F8) 2 Inversions with Reflex to Sequencing and Reflex to Deletion/Duplication (2001614) is recommended.

Mnemonic
F8 FGS
Methodology

Polymerase Chain Reaction/Sequencing

Performed

Varies

Reported

21-28 days

New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
Collect

Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).

Specimen Preparation

Transport 3 mL whole blood. (Min: 1 mL)

Storage/Transport Temperature

Refrigerated.

Unacceptable Conditions
Remarks
Stability

Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable

Reference Interval
Interpretive Data

Background Information for Hemophilia A (F8) Sequencing:
Characteristics:
Severe deficiency of factor VIII clotting activity leading to spontaneous joint or deep muscle bleeding.  Moderate to mild deficiency is associated with prolonged bleeding after tooth extractions, surgery, or injuries and recurrent or delayed wound healing.
Incidence: 1 in 4,000-5,000 live male births worldwide, rare in females.
Inheritance: X-linked recessive. Of simplex cases, 85 percent of mothers are carriers and 10-15 percent of boys have a de novo mutation.
Penetrance: 100 percent in males and 10 percent in females.
Cause: Deleterious F8 gene mutations.
Clinical Sensitivity: 98 percent of mutations causing mild to moderate hemophilia A and 43 percent of severe hemophilia A mutations are detected by sequencing.
Methodology: Bidirectional sequencing of the entire F8 coding region and intron-exon boundaries.
Analytical Sensitivity and Specificity: 99 percent.
Limitations: Diagnostic errors can occur due to rare sequence variations. Regulatory region mutations, deep intronic mutations and gene duplications will not be detected in patients of either sex; large deletions will not be detected in females.

Compliance Statement C: For human genetic inheritable conditions and mutations. This test was developed and its performance characteristics determined by ARUP Laboratories. The U. S. Food and Drug Administration has not approved or cleared this test; however, FDA clearance or approval is not currently required for clinical use. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions.

Counseling and informed consent are recommended for genetic testing. Consent forms are available online.

Note
Hotline History
N/A
Components
Component Test Code* Component Chart Name LOINC
2001749 Hemophilia A (F8) Sequencing Interp
2001750 F8 FGS Specimen
* 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.
Aliases
  • F8
  • Factor VIII
  • Hemophilia A mild or moderate, molecular assay
  • Hemophlia A sequencing assay
Hemophilia A (F8) Sequencing