Ordering Recommendation

Detect causal F8 variant in individuals with established severe hemophilia A and determine carrier status in at-risk females with severely affected male relatives. For mild to moderate hemophilia A, Hemophilia A (F8) sequencing (2001747) is preferred.

Mnemonic
F8 COMP
Methodology

Inverse Polymerase Chain Reaction/Sequencing/Multiplex Ligation-dependent Probe Amplification

Performed

Varies

Reported

28-35 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: 2 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) 2 Inversions with Reflex to Sequencing and Reflex to Deletion/Duplication:
Characteristics: Severe deficiency of factor VIII clotting activity is associated with spontaneous joint or deep tissue bleeding. Moderate or 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.
Methodology for Inversions: F8 intron 22-A and intron 1 inversions detected by inverse PCR and electrophoresis.
Methodology for Sequencing: Bidirectional sequencing of the F8 coding region and intron-exon boundaries.
Methodology for Deletion/Duplication: Multiplex ligation-dependent probe amplification (MLPA) to detect large deletions/duplications in the F8 coding region.
Analytical Sensitivity & Specificity: 99 percent.
Limitations: Diagnostic errors can occur due to rare sequence variations. Regulatory region and deep intronic mutations, other than the F8 intron 22-A and intron 1 inversions, will not be detected. Deletions/duplications in exon 23 will not be detected.

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

F8 inversion testing is performed on all specimens. If inversion testing does not explain the clinical scenario, then F8 gene sequencing will be added. If inversion testing and sequencing does not explain the clinical scenario, then deletion/duplication testing will be added. Additional charges apply.

Hotline History
N/A
CPT Codes

81403; if reflexed to Seq, add 81407; if reflexed to Del/Dup, add 81406

Components
Component Test Code* Component Chart Name LOINC
2001616 Family History for Hemophilia A (F8)
2001617 F8 COMP Specimen
2001618 Symptoms for Hemophilia A (F8)
2001620 Hemophilia A (F8) Interpretation
* 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
  • Carrier Detection and Prenatal Diagnosis
  • Carrier Detection of Hemophilia A
  • DNA Analysis for Hemophilia A
  • F8
  • Factor VIII
  • Factor VIII Deficiency
  • Factor VIII Inversion
  • Hemophilia A
  • Hemophilia A carrier status panel
  • Hemophilia A cascade molecular testing
  • Hemophilia A reflex panel
  • Hemophilia A severe, comprehensive reflex panel
  • Severe Hemophilia A
Hemophilia A (F8) 2 Inversions with Reflex to Sequencing and Reflex to Deletion/Duplication