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Hemoglobin Electrophoresis Interpretation

A written summary of your hemoglobin test pattern that names the types of hemoglobin found, such as a normal pattern or a carrier state.

AI-verified against cited sources. Awaiting expert reviewAlso called Hb Pattern, Hgb PatternLOINC 49316-3

What it is

A hemoglobin evaluation separates the types of hemoglobin in your blood by HPLC, capillary electrophoresis or both. A trained pathologist or hematologist then writes a summary of the pattern. Typical wording includes a normal pattern, a carrier state such as sickle cell trait or beta-thalassemia trait, or a pattern that needs more testing. The summary draws on the percentages of each hemoglobin (A, A2, F, S, C and others), your red blood cell indices, and any recent transfusions.

Why it matters

This is the part of the report that puts the numbers into words. It matters because many hemoglobin patterns, such as carrier states, cause no symptoms but can be passed to children, and some can look like iron deficiency on a CBC. An inherited pattern usually stays the same for life, so one good evaluation is often all a person needs, unless a transfusion or treatment changes the picture.

What can affect your result

  • A recent blood transfusion, which blurs the pattern
  • Iron deficiency, which can lower HbA2 and hide beta-thalassemia trait
  • Age: babies make mostly fetal hemoglobin, so the pattern differs in the first two years
  • Treatment that changes HbF, such as hydroxyurea
  • The method used (HPLC or capillary electrophoresis) and each lab's wording
  • Alpha-thalassemia trait, which is often not visible on electrophoresis
  • A recent blood transfusion mixes donor red cells with yours and can make the pattern ambiguous. One hospital lab does not run the test within three months of a transfusion.
  • Iron deficiency can lower HbA2 and hide beta-thalassemia trait.
  • Alpha-thalassemia trait usually looks normal on electrophoresis, so the report may say it cannot be excluded.
  • HPLC and capillary electrophoresis can miss or mix up some variants, for example HbS and HbC can run together on some HPLC systems, so labs may add a second method.
  • Treatment that changes HbF, such as hydroxyurea, changes the pattern.

An inherited hemoglobin pattern stays the same for life. It can look different after a transfusion or treatment, and babies show a different pattern until about age two.

When to talk to a clinician

A pattern that names a trait or variant is not urgent by itself. Share the full report with your clinician, especially before a pregnancy or if you have ongoing tiredness. If you have been told you have a sickle cell disease or severe thalassemia pattern, follow your care team's plan. Call 911 or your local emergency number for chest pain, trouble breathing, sudden weakness on one side of the body or trouble speaking.

Questions you could ask

  • Does this pattern explain my small red blood cells?
  • Should my partner or family members be offered testing?
  • Do I need any follow-up testing, such as DNA testing?

Questions people ask

Does a trait pattern mean I am sick?

No. Carrier states such as sickle cell trait and beta-thalassemia trait usually cause no illness. They matter mostly for family planning, because two carriers can have a child with a more serious condition, and in some rare situations such as extreme exertion for sickle cell trait. Your clinician can explain what your pattern means for you.

Will I need this test again?

Often no. Inherited hemoglobin patterns do not change, so the American Society for Clinical Pathology advises against repeating hemoglobin electrophoresis in people who already have a result and do not need treatment or monitoring. A repeat can make sense after a transfusion or to track a treatment.

Why does my report say alpha-thalassemia 'cannot be excluded'?

Alpha-thalassemia trait usually looks normal on electrophoresis, so this test cannot rule it out. If your red blood cells are small and your iron is normal, your clinician may suggest DNA testing to look for it.

Show the science and sources

For clinicians and researchers

Mayo's hemoglobin electrophoresis evaluation always includes HbA2 and HbF by capillary electrophoresis and cation-exchange HPLC, with a hematopathologist interpretation and reflex testing that can include a sickle solubility test, isoelectric focusing, mass spectrometry, stability tests, HbF distribution by flow cytometry and DNA sequencing or deletion/duplication analysis of the alpha, beta and gamma globin genes. ARUP's evaluation runs HPLC with reflex to capillary electrophoresis and/or RBC solubility. The University of Iowa pairs capillary electrophoresis with a smear review and a pathologist narrative, and notes that analysis cannot be done within three months of a transfusion. AAFP lists typical patterns: normal or alpha-thalassemia trait HbA over 95%, HbA2 2% to 3.5%, HbF under 1%; beta-thalassemia trait HbA over 90%, HbA2 3.5% to 9%, HbF 0.1% to 5%. The NHS England screening handbook reads relative proportions of a variant as typical at 30% to 40% (25% to 35% for HbE), prompts a check that the HbA peak is real at 40% to 50%, suggests variant with beta-plus thalassemia at 50% or more, and suggests a carrier with coexisting alpha-thalassemia or iron deficiency at 30% or less with MCH under 25 pg. Its HbA2 action value is 3.5% or more. HPLC and capillary electrophoresis cannot separate every variant, and HbS and HbC can co-elute on some HPLC systems. Alpha-thalassemia carriers usually have a normal electrophoresis, so DNA testing is needed to confirm. LOINC has many pattern codes by method and wording; 49316-3 is the by-electrophoresis interpretation code and labs also use the narrative, HPLC and capillary electrophoresis versions.

LOINC 49316-3 (primary), 12710-0, 13514-5, 78748-1, 49322-1, 42247-7, 21026-0. Specimen: whole-blood.

Sources

  1. Hemoglobin Electrophoresis Evaluation, Blood (test HBEL1), Mayo Clinic Laboratories
  2. Hemoglobin Evaluation by HPLC With Reflex to Electrophoresis and/or RBC Solubility (test 3017101), ARUP Laboratories
  3. Hemoglobin Evaluation, Quantitation with Interpretation (Pathology Handbook), University of Iowa Hospitals & Clinics
  4. Alpha- and Beta-thalassemia: Rapid Evidence Review, American Family Physician (2022)
  5. Sickle cell and thalassaemia screening: laboratory handbook, Antenatal screening (updated 10 October 2024), NHS England (NHS Sickle Cell and Thalassaemia Screening Programme) (2024)
  6. Sickle cell and thalassaemia screening: laboratory handbook, Interpretation and reporting of antenatal screening results, NHS England (NHS Sickle Cell and Thalassaemia Screening Programme)

AI-verified against cited sources. Awaiting expert review. Last reviewed 2026-10-03. How we build and check these pages.

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