Normal Hemoglobin Electrophoresis Pattern in an Adult
These hemoglobin electrophoresis results (Hgb A 97.9%, Hgb F <1%, Hgb A2 2.1%) represent a completely normal adult hemoglobin pattern and require no further evaluation or intervention.
Interpretation of Results
Normal Adult Hemoglobin Distribution
- Hemoglobin A (97.9%): This is within the normal range for adults, where Hgb A typically comprises 95-98% of total hemoglobin 1
- Hemoglobin F (<1%): Fetal hemoglobin normally decreases to less than 1-2% by 6-12 months of age and remains at this low level throughout adult life 2
- Hemoglobin A2 (2.1%): This falls within the normal adult range of approximately 2.0-3.5%, with healthy individuals typically having about 2.5% 3, 1
Clinical Significance
This pattern effectively rules out common hemoglobinopathies:
Beta-thalassemia trait is excluded because Hgb A2 is not elevated above 3.5% 3. In beta-thalassemia carriers, Hgb A2 levels are typically ≥3.5% and represent the most significant diagnostic parameter 3
Hereditary persistence of fetal hemoglobin (HPFH) is excluded because Hgb F is appropriately low at <1% 2. HPFH would show persistently elevated fetal hemoglobin levels in adults 2, 4
Sickle cell disease and trait are excluded by the absence of hemoglobin S on electrophoresis 4
Iron deficiency is unlikely as this condition typically suppresses Hgb A2 levels below normal, with the lowest levels seen in severe anemia 1
Common Pitfalls to Avoid
Do not confuse normal Hgb A2 levels (2.0-3.5%) with elevated levels (≥3.5%) that indicate beta-thalassemia trait 3
Do not misinterpret trace fetal hemoglobin (<1%) as pathological - this is the expected physiological state in adults after the first year of life 2
Do not order additional hemoglobinopathy testing in the absence of anemia, abnormal red cell indices, or clinical symptoms, as this normal pattern requires no further workup 1