Test Directory
Factor IX (9) Duplication/Deletion Analysis by MLPA
Justification
Hemophilia B is due to mutations in the Factor IX (9) gene. Knowing the mutation can inform likelihood of inhibitor development, bleeding severity, family planning, and pregnancy and neonatal management. Over 10% of severe hemophilia B cases are due to large deletion or duplication variants which are very difficult to detect via sequencing.
STAT: < 48 hours (M-F)
MLPA
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 | MLPA |
STAT TAT | < 48 hours (M-F) |
STAT TAT Performance | > 90% of results released in 48 hours |
ROUTINE TAT | < 5 days (M-F) |
ALTERNATIVE NAMES | Hemophilia B, FIX (9) copy number variant (CNV) analysis |
DESCRIPTION | This test looks for deletions or duplications within the F9 gene by multiplex ligation-dependent probe amplification (MLPA), a method with much higher resolution than next-generation sequencing or microarrays. |
LIMITATIONS | This test detects deletions and duplications but not balanced structural variants (i.e., inversions, insertions or translocations). This test requires two consecutive probes indicating a deletion or duplication to make a CNV call. |
NORMAL RANGE | Interpretation: Negative |
ASSOCIATED TESTING | - |
REFERENCES | Johnsen JM, et al. Novel approach to genetic analysis and results in 3000 hemophilia patients enrolled in the My Life, Our Future initiative. Blood Adv. 2017 May 18;1(13):824-834. |
SAMPLE REPORT | Upon request |
NEW YORK STATE APPROVED | No |
Test Codes
ORDER CODE | P3399 |
CPT CODE | 81479 |
LOINC CODE | 93811-8 |