Test Code F81P Hemophilia A F8 Gene, Intron 1 Inversion Known Mutation Analysis, Prenatal
Useful For
Prenatal testing for hemophilia A when a F8 intron 1 inversion has been identified in a family member
Disease States
- Hemophilia A
Reflex Tests
Test ID | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
CULAF | Amniotic Fluid Culture/Genetic Test | Yes | No |
CULFB | Fibroblast Culture for Genetic Test | Yes | No |
MATCC | Maternal Cell Contamination, B | Yes | No |
Testing Algorithm
If amniotic fluid is received, amniotic fluid culture/genetic test will be added at an additional charge.
If chorionic villus specimen is received, fibroblast culture for genetic test will be added at an additional charge.
For any prenatal specimen that is received, maternal cell contamination studies will be added. A maternal whole blood specimen is required to perform this test.
The following algorithms are available:
Special Instructions
Reporting Name
HA F8 Intron 1 Inversion, AF or CVSSpecimen Type
VariesAdditional Testing Requirements
Due to its complexity, consultation with the laboratory is required for all prenatal testing; call 800-533-1710 to speak to a genetic counselor.
All prenatal specimens must be accompanied by a maternal blood specimen. Order MATCC / Maternal Cell Contamination, Molecular Analysis, Varies on the maternal specimen.
Shipping Instructions
Advise Express Mail or equivalent if not on courier service.
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
Results will be reported and telephoned or faxed, if requested.
Submit only 1 of the following specimens:
Specimen Type: Amniotic fluid
Container/Tube: Amniotic fluid container
Specimen Volume: 5-10 mL
Collection Instructions:
1. Optimal timing for specimen collection is during 14 to 18 weeks of gestation, but specimens collected at other weeks of gestation are also accepted.
2. Discard the first 2 mL of amniotic fluid. If the culture will be performed in conjunction with chromosome analysis and alpha-fetoprotein, a total of approximately 25 to 30 mL will be needed for the combined studies.
Specimen Stability Information: Ambient (preferred) <24 hours/Refrigerated
Additional Information:
1. Place the tubes in a Styrofoam container.
2. Fill remaining space with packing material.
3. Unavoidably, about 1% to 2% of mailed-in specimens are not viable.
4. Bloody specimens are undesirable.
5. If the specimen does not grow in culture, you will be notified within 7 days of receipt.
6. A separate culture charge will be assessed under CULAF / Culture for Genetic Testing, Amniotic Fluid.
7. All prenatal specimens must be accompanied by a maternal blood specimen; order MATCC / Maternal Cell Contamination, Molecular Analysis, Varies on the maternal specimen.
Specimen Type: Chorionic villi
Supplies: CVS Media (RPMI) and Small Dish (T095)
Container/Tube: 15-mL tube containing 15 mL of transport media
Specimen Volume: 20-30 mg
Collection Instructions:
1. Collect specimen by the transabdominal or transcervical method.
2. Transfer the chorionic villi specimen to a Petri dish containing transport medium.
3. Using a stereomicroscope and sterile forceps, assess the quality and quantity of the villi and remove any blood clots and maternal decidua.
Specimen Stability Information: Refrigerated (preferred) <24 hours/Ambient
Additional Information:
1. A separate culture charge will be assessed under CULFB / Fibroblast Culture for Biochemical or Molecular Testing. An additional 3 to 4 weeks is required to culture fibroblasts before genetic testing can occur.
2. All prenatal specimens must be accompanied by a maternal blood specimen; order MATCC / Maternal Cell Contamination, Molecular Analysis, Varies on the maternal specimen.
Specimen Type: Confluent cultured cells
Container/Tube: T-25 flask
Specimen Volume: 2 Flasks approximately 90% confluent
Collection Instructions: Submit confluent cultured cells from another laboratory.
Specimen Stability Information: Ambient (preferred) <24 hours/Refrigerated
Additional Information: All prenatal specimens must be accompanied by a maternal blood specimen; order MATCC / Maternal Cell Contamination, Molecular Analysis, Varies on the maternal specimen.
Specimen Minimum Volume
Amniotic fluid: See Specimen Required
Chorionic villi: 5 mg
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Varies | Varies |
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Genetics Test Information
This test detects the intron 1 inversion in the F8 gene. The intron 1 inversion variant accounts for approximately 5% of variants associated with severe hemophilia A.
Intron 1 inversion known variant analysis on a prenatal specimen can only be performed when there is a known intron 1 inversion in the family.
Reference Values
An interpretive report will be provided.
Day(s) Performed
Monday through Friday
Report Available
28 to 35 daysSpecimen Retention Time
Extracted DNA: Indefinitely, from New York State: 90 daysPerforming Laboratory
Mayo Clinic Laboratories in RochesterCPT Code Information
81403
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
F81P | HA F8 Intron 1 Inversion, AF or CVS | 82342-7 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
35138 | HA F8 Int1 KM Reason for Referral | 42349-1 |
35004 | HA F8 Intron 1 Inversion, AF or CVS | 82342-7 |
35005 | F81P Interpretation | 69047-9 |
35006 | 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.