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Hemophilia B (F9) Sequencing
2001578
Ordering Recommendation

Acceptable test to confirm diagnosis or determine carrier status for F9 gene variants.

Mnemonic
F9 FGS
Methodology
Polymerase Chain Reaction/Sequencing
Performed
Varies
Reported
14-21 days
New York DOH Approval Status
This test is New York DOH approved.
ARUP Consult®
Disease Topics
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 B (F9) Sequencing:
Characteristics:
Severe deficiency of factor IX 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 25,000 males worldwide.
Penetrance: 100 percent in males and 10 percent in females.
Inheritance: X-linked recessive.
Cause: Deleterious F9 gene mutations.
Clinical Sensitivity: 97 percent.
Methodology: Bidirectional sequencing of the entire F9 coding region and intron-exon boundaries and proximal promoter.
Analytical Sensitivity and Specificity: 99 percent.
Limitations:Diagnostic errors can occur due to rare sequence variations. 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: The performance characteristics of this test were validated by ARUP Laboratories. The U.S. Food and Drug Administration (FDA) has not approved or cleared this test. However, FDA approval or clearance is currently not required for clinical use of this test. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions. ARUP is authorized under Clinical Laboratory Improvement Amendments (CLIA) and by all states to perform high-complexity testing. Counseling and informed consent are recommended for genetic testing. Consent forms are available online.

Components
Component Test Code*Component Chart NameLOINC
2001580Hemophilia B Interpretation
2001581F9 FGS Specimen
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Aliases
  • Christmas Disease
  • F9
  • F9 sequencing
  • Factor IX