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Test ID BLOD0437 Hemoglobin Electrophoresis Cascade, Blood

Useful For

Diagnosis and comprehensive classification of thalassemias and hemoglobin variants

Specimen Type

Whole Blood EDTA


Advisory Information


Alpha-thalassemias with only 1 or 2 alpha-globin gene deletions are not recognized by this testing protocol. ATHAL / Alpha-Globin Gene Analysis is required to identify 1 or 2 globin gene deletions.



Necessary Information


Include recent transfusion information.

 

Include most recent CBC results.



Specimen Required


Container/Tube:

Preferred: Lavender top (EDTA)

Acceptable: ACD (solution B), green top (sodium heparin)

Specimen Volume: 10 mL

Collection Instructions: Send specimen in original tube. Do not aliquot.


Reject Due To

Hemolysis

NA

Lipemia

NA

Icterus

NA

Other

NA

Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time
Whole Blood EDTA Refrigerated 7 days

Day(s) and Time(s) Performed

Monday through Saturday 

Analytic Time

2 to 25 days if structural and/or molecular studies are required

Method Name

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

Performing Laboratory

Mayo Clinic Laboratories in Rochester

CPT Code Information

Hemoglobin Electrophoresis Cascade

83020-Quantitation by electrophoresis

83021-Quantitation by HPLC

 

IEF Confirms

82664-Electrophoresis, not elsewhere specified (if appropriate)

 

Hemoglobin, Unstable, Blood

83068 (if appropriate)

 

Hemoglobin Variant by Mass Spectrometry (MS), Blood

83789 (if appropriate)

 

Hemoglobin F, Red Blood Cell Distribution, Blood

88184 (if appropriate)

Reporting Name

HGB Electrophoresis Cascade

Profile Information

Test ID Reporting Name Available Separately Always Performed
A2F Hemoglobin A2 and F No Yes
HBEL Hemoglobin Electrophoresis, B No Yes

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
SDEX Hemoglobin S, Scrn, B Yes No
IEF IEF Confirms No No
MASS Hb Variant by Mass Spec, B No No
UNHB Unstable Hemoglobin, B No No
ATHAL Alpha-Globin Gene Analysis Yes No
WASQR Alpha Globin Gene Sequencing, B Yes, (Order WASEQ) No
WBSQR Beta Globin Gene Sequencing, B Yes, (Order WBSEQ) No
WBDDR Beta Globin Cluster Locus Del/Dup,B Yes, (Order WBDD) No
WGSQR Gamma Globin Full Gene Sequencing Yes, (Order WGSEQ) No
HBELA HGB Electrophoresis Summary Interp No No
HPFH Hemoglobin F, Red Cell Distrib, B No No

Testing Algorithm

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.

Reference Values

HEMOGLOBIN A

1-30 days: 5.9-77.2%

1-2 months: 7.9-92.4%

3-5 months: 54.7-97.1%

6-8 months: 80.0-98.0%

9-12 months: 86.2-98.0%

13-17 months: 88.8-98.0%

18-23 months: 90.4-98.0%

≥24 months: 95.8-98.0%

 

HEMOGLOBIN A2

1-30 days: 0.0-2.1%

1-2 months: 0.0-2.6%

3-5 months: 1.3-3.1%

≥6 months: 2.0-3.3%

 

HEMOGLOBIN F

1-30 days: 22.8-92.0%

1-2 months: 7.6-89.8%

3-5 months: 1.6-42.2%

6-8 months: 0.0-16.7%

9-12 months: 0.0-10.5%

13-17 months: 0.0-7.9%

18-23 months: 0.0-6.3%

≥24 months: 0.0-0.9%

 

VARIANT

No abnormal variants

 

VARIANT 2

No abnormal variants

 

VARIANT 3

No abnormal variants

Test Classification

This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

Forms

1. 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 in Special Instructions:

-Informed Consent for Genetic Testing (T576)

-Informed Consent for Genetic Testing-Spanish (T826)

2. Metabolic Hematology Patient Information (T810) in Special Instructions

3. If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:

-General Request (T239)

-Benign Hematology Test Request (T755)

Sanford Laboratories - Fargo Additional Information:

SANFORD INTERFACE BUILD INFORMATION

Result Code Result Code Description
13537 Hemoglobin A2
13538 Hemoglobin F
13532 Hemoglobin A
13533 Variant
13534 Variant 2
13535 Variant 3
13536 Interpretation