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HelpTest Code F81B Hemophilia A F8 Gene, Intron 1 Inversion Known Mutation, Blood
Useful For
First-tier molecular testing for male patients affected with severe hemophilia A, when a familial intron 1 inversion has been previously identified
Determining hemophilia A carrier status for at-risk female patients, ie, individuals with a family history of severe hemophilia A due to F8 intron 1 inversion
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| MATCC | Maternal Cell Contamination, B | Yes | No |
Testing Algorithm
For any postnatal umbilical cord blood specimen that is received, maternal cell contamination studies will be performed at an additional charge. A maternal whole blood specimen is required to perform this test. See Additional Testing Requirements.
For more information the following algorithms are available:
Special Instructions
Reporting Name
HA F8 Intron 1 Inversion KM, BSpecimen Type
Whole bloodOrdering Guidance
This test should be ordered for whole blood or postnatal umbilical cord specimens when an intron 1 inversion has previously been identified in the family. For prenatal specimens order F81P / Hemophilia A F8 Gene, Intron 1 Inversion Known Mutation Analysis, Prenatal.
If a familial variant has not been identified in a severely affected hemophilia A patient, order F8INV / Hemophilia A F8 Gene, Intron 1 and 22 Inversion Mutation Analysis, Blood.
For evaluation of a patient with bleeding symptoms and no known personal history of a bleeding disorder consider ALBLD / Bleeding Diathesis Profile, Limited, Plasma or the specific factor assays.
Additional Testing Requirements
Due to the complexity of testing, consultation with the laboratory is required for all postnatal umbilical cord blood specimens; call 800-533-1710 to speak to a genetic counselor.
All postnatal umbilical cord specimens must be accompanied by a maternal blood specimen. Order this test on the cord blood specimen (only 1 specimen tube required) and order MATCC / Maternal Cell Contamination, Molecular Analysis, Varies on the maternal specimen.
Additional Testing Requirements
Due to the complexity of testing nonperipheral blood, consultation with the laboratory is required for all cord blood samples. Order this test on the cord blood specimen (only 1 specimen tube required) and order MATCC / Maternal Cell Contamination, Molecular Analysis, Blood on the maternal specimen.
Necessary Information
Hemophilia A Patient Information (T712) is required. Testing may proceed without the patient information, however, the information aids in providing a more thorough interpretation. Ordering providers are strongly encouraged to fill out the form and send with the specimen.
Specimen Required
Patient Preparation: A previous bone marrow transplant from an allogeneic donor will interfere with testing. For information about testing patients who have received a bone marrow transplant, call 800-533-1710.
Container/Tube:
Preferred: Lavender top (EDTA)
Acceptable: Yellow top (ACD) or blue top (3.2% sodium citrate)
Specimen Volume: 4 mL
Collection Instructions:
1. Invert several times to mix blood.
2. Send whole blood specimen in original tube. Do not aliquot.
3. Whole blood collected postnatal from an umbilical cord is also acceptable if approved by the laboratory. See Additional Information.
Additional Information:
1. To ensure minimum volume and concentration of DNA are met, the requested volume must be submitted. Testing may be canceled if DNA requirements are inadequate.
2. For postnatal umbilical cord whole blood specimens, maternal cell contamination studies are performed to ensure test results reflect that of the patient tested. A maternal blood specimen is required to complete maternal cell contamination studies. Order MATCC / Maternal Cell Contamination, Molecular Analysis, Varies on the maternal blood specimen under a separate order number.
Specimen Minimum Volume
1 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Whole blood | Ambient (preferred) | 7 days |
| Frozen | 7 days | |
| Refrigerated | 7 days |
Reject Due To
| Gross hemolysis | OK |
| Gross lipemia | OK |
Reference Values
An interpretive report will be provided.
Day(s) Performed
Weekly
Report Available
14 to 21 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
81403
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| F81B | HA F8 Intron 1 Inversion KM, B | 81762-7 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 35137 | HA F8 Int1 KM Reason for Referral | 42349-1 |
| 35001 | HA F8 Intron 1 Inversion KM, B | 81762-7 |
| 35002 | F81B Interpretation | 69047-9 |
| 35003 | HA F8 Int1 KM Reviewed By | 18771-6 |
Forms
1. Hemophilia A Patient Information (T712) is required.
2. New York Clients-Informed consent is required. Document on the request form or electronic order that a copy is on file. The following documents are available:
-Informed Consent for Genetic Testing (T576)
-Informed Consent for Genetic Testing-Spanish (T826)
3. If not ordering electronically, complete, print, and send a Coagulation Test Request (T753) with the specimen.