Test Directory
Factor IX (9) Gene Sequencing Assay
Justification
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.
STAT: < 48 hours (M-F)
NGS
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 |
ALTERNATIVE | Cheek swab | 2 swab | - | Room Temp.: 1 month Refrigerated: 1 month |
REJECTION CRITERIA | Sample contamination; sample compromised |
SPECIAL INSTRUCTIONS | - |
General Information
METHODOLOGY | NGS |
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 9, F9, Factor IX, FIX, Hemophilia B, Christmas disease |
DESCRIPTION | This test sequences the exons plus 5bp of the flanking introns of F9, plus deep intronic and promoter mutations that have been associated with disease. Sanger sequencing may be used to confirm variants as needed. Hemophilia B has a prevalence of 1:25000. |
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 |
ASSOCIATED TESTING | - |
REFERENCES | 1.) Santagostino E and Fasulo MR. Semin Thromb Hemost 2013;39(7):697-701; |
SAMPLE REPORT | Upon request |
NEW YORK STATE APPROVED | No |
Test Codes
ORDER CODE | P3389 |
CPT CODE | 81238 |
LOINC CODE | 93811-8 |