Test Catalog

Test ID: THEVP    
Thalassemia and Hemoglobinopathy Evaluation

Testing Algorithm Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

This is a consultative evaluation in which the case will be evaluated at Mayo Clinic Laboratories, the appropriate tests performed at an additional charge, and the results interpreted.

 

This evaluation will always include hemoglobin A(2) and F and hemoglobin electrophoresis utilizing cation exchange HPLC and capillary electrophoresis methods.

 

If a serum sample is received, a serum ferritin will always be performed to allow incorporation of possible iron deficiency into profile interpretation and economical test utilization. If the ferritin component is not desired, do not send a serum sample and none will be performed or charged. Fill out the Thalassemia/Hemoglobinopathy Patient Information sheet (T358) and indicate the CBC values and ferritin levels for a more complete evaluation.

Note: If a ferritin is not done or provided, and if microcytosis is present and no other abnormalities are found, the case will be reflexed to alpha-globin gene analysis.

 

Hemoglobin electrophoresis reflex testing, performed at additional charge, may include any or all of the following as indicated 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, please utilize the appropriate check boxes in 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.

 

Thalassemia Summary Interpretation, an additional consultative interpretation that summarizes all testing, will be provided after test completion to incorporate subsequent results into overall evaluation if any of the following molecular tests are reflexed on the Thalassemia and Hemoglobinopathy Evaluation:

-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.

Specimen Type Describes the specimen type validated for testing

Serum
Whole Blood EDTA

Necessary Information

1. Include recent transfusion information.

2. Include most recent CBC results.

Specimen Required Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Both blood and serum are required.

 

Specimen Type: Whole blood

Container/Tube: Lavender top (EDTA)

Specimen Volume: 15 mL

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

 

Specimen Type: Serum

Container/Tube: Red top or serum gel

Specimen Volume: 0.6 mL

Collection Instructions: Label specimen as serum.

Special Instructions Library of PDFs including pertinent information and forms related to the test

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 a Benign Hematology Test Request Form (T755) with the specimen.

Specimen Minimum Volume Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory

Blood: 2.5 mL; Serum: 0.5 mL

Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected

Gross hemolysis

Reject

Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen TypeTemperatureTime
SerumRefrigerated7 days
Whole Blood EDTARefrigerated7 days