This is a second tier test and REQUIRES PERMISSION from ARUP's Genetic Counselor (800-242-2787, x2141) before ordering. Preferred initial test is the sequencing and deletion/duplication test.
- Patient Preparation
- Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).
- Specimen Preparation
- Transport 3 mL whole blood. (Min: 2 mL)
- Storage/Transport Temperature
- Unacceptable Conditions
- Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable
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: Pathogenic F9 gene mutations.
Clinical Sensitivity: 3 percent.
Methodology: Multiplex Ligation-dependent Probe Amplification (MLPA) to detect large F9 deletions/duplications.
Analytical Sensitivity and Specificity: 99 percent.
Limitations: Diagnostic errors can occur due to rare sequence variations. Large deletions/duplications in exon 1 may not be detected. Regulatory region mutations, deep intronic mutations, single base pair substitutions, and small deletions/duplications will not be identified.
|Component Test Code*||Component Chart Name||LOINC|
|2010500||Hemophilia B (F9) DelDup Specimen||31208-2|
|2010501||Hemophilia B (F9) DelDup Interp||38896-7|
- Christmas Disease
- Factor IX Deficiency