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Test Code F81B Hemophilia A F8 Gene, Intron 1 Inversion Known Mutation, Whole 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

Testing Algorithm

Maternal cell contamination testing will be performed for all cord blood specimens. A maternal whole blood sample with an order for MATCC / Maternal Cell Contamination, Molecular Analysis, Blood is required to perform this test. See Additional Testing Requirements.

 

The following algorithms are available:

-Hemophilia Carrier Testing Algorithm

-Hemophilia Testing Algorithm

Reporting Name

HA F8 Intron 1 Inversion KM, B

Specimen Type

Whole blood


Ordering Guidance


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, Whole 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 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 allogenic donor will interfere with testing. Call 800-533-1710 for instructions for testing patients who have received a bone marrow transplant.

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.


Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Whole blood Ambient (preferred) 7 days
  Frozen  7 days
  Refrigerated  7 days

Reference Values

An interpretive report will be provided.

Day(s) Performed

Weekly

Report Available

14 to 21 days

Performing 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

Method Name

Polymerase Chain Reaction (PCR)

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.