Hemoglobin electrophoresis cascade will always include hemoglobin A(2) and F and hemoglobin electrophoresis utilizing cation exchange HPLC and capillary electrophoresis methods.
Hemoglobin electrophoresis reflex testing, performed at additional charge, may include any or all of the following to identify rare hemoglobin variants present: sickle solubility (hemoglobin S screen), hemoglobin heat and isopropanol stability studies (unstable hemoglobin), isoelectric focusing, intact globin chain mass spectrometry (hemoglobin variant by mass spectrometry), Hb F distribution by flow cytometry (hemoglobin F red cell distribution), DNA (Sanger) testing for beta chain variants and the most common beta thalassemias (beta-globin gene sequencing), multiplex ligation-dependent probe amplification (MLPA) testing for beta cluster locus large deletions and duplications, including large deletional hereditary persistence of fetal hemoglobin (HPFH), delta-beta (DBT), delta thalassemias, gamma-delta-beta (GDBT), and epsilon-gamma-delta-beta (EGDBT) thalassemias (beta globin cluster locus del/dup), large deletional alpha thalassemias and alpha gene duplications (alpha-globin gene analysis), alpha chain variants and non-deletional alpha thalassemias (alpha-globin gene sequencing), and gamma chain variants and non-deletional HPFH (gamma globin full gene sequencing).
If a Thalassemia/Hemoglobinopathy Patient Information sheet (T358) is received with the sample, the reported clinical features or clinical impression will be considered in the interpretation and focus of the evaluation. Our laboratory has extensive experience in hemoglobin variant identification and many cases can be confidently classified without molecular testing. However, molecular confirmation is always available. If no molecular testing or, conversely, specific molecular tests are desired, utilize the appropriate check boxes on the information sheet. If the information sheet or other communication is not received, the reviewing hematopathologist will select appropriate tests to sufficiently explain the clinical impression or reported CBC results, which may or may not include molecular testing.
Hemoglobin (HGB) Electrophoresis Summary Interpretation, an additional consultative interpretation that summarizes all testing, will be provided after test completion to incorporate subsequent results into an overall evaluation if 1 or more of the following molecular tests are reflexed on the HBELC / Hemoglobin Electrophoresis Cascade, Blood:
-ATHAL / Alpha-Globin Gene Analysis
-WASQR / Alpha-Globin Gene Sequencing, Blood
-WBSQR / Beta-Globin Gene Sequencing, Blood
-WBDDR / Beta-Globin Cluster Locus Deletion/Duplication, Blood
-WGSQR / Gamma-Globin Full Gene Sequencing
See Benign Hematology Evaluation Comparison in Special Instructions.
A2F: Cation Exchange/High-Performance Liquid Chromatography (HPLC)
HBEL: Capillary Electrophoresis
IEF: Isoelectric Focusing
MASS: Mass Spectrometry (MS)
HPFH: Flow Cytometry
UNHB: Isopropanol and Heat Stability
HBELA: Consultative Interpretation
