Hemoglobin F (HbF) Variant Test, Qualitative
This qualitative laboratory test looks for the presence of a specified hemoglobin F variant. It reports whether the targeted variant was detected rather than measuring the amount of HbF.
["A detected result may help explain unusual hemoglobin findings or guide counseling about a possible inherited blood condition."]
Key facts at a glance
- LOINC
- 28006-5
- Short code
- Hgb F Vom Ql
- Synonyms
- Hgb F Vom Ql
- Category
- hematology
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 12
- Ref high
- 17.5
- Critical range
- 7 N/A – 20 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 85018
- SNOMED
- 900000000000003004
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
What This Test Looks For
Hemoglobin F is normally present in red blood cells, particularly in newborns and during pregnancy. This test checks for a particular genetic change that may alter the structure or production of hemoglobin.
How the Result Is Reported
A “detected” or positive result means the targeted variant was found. A “not detected” result means that the specific variant tested for was not found; it does not exclude every possible hemoglobin disorder.
Why the Test May Be Ordered
A clinician may order this test after unexpected hemoglobin test results, family studies, or evaluation of an inherited anemia or hemoglobin disorder. The results are most helpful when reviewed alongside other laboratory and family information.
Important Limitations
This test examines only the variant or variants included by the laboratory. It may not detect other hemoglobin conditions, deletions, or genetic changes, and results should be interpreted by a qualified healthcare professional.
Reference range
Adult males: 13.5-17.5 g/dL; Females: 12.0-16.0 g/dLN/A
No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
HbF variant analysis
Frequently asked questions
What does a “detected” result mean?
Does a “not detected” result rule out a hemoglobin disorder?
No. This is a qualitative variant test. It looks for the presence of a targeted HbF genetic change rather than measuring total HbF or separating all hemoglobin types.
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy