Test Id : THEVI
Hemoglobinopathy Interpretation
Useful For
Suggests clinical disorders or settings where the test may be helpful
Interpretation of results for the evaluation of thalassemias and hemoglobinopathies
Evaluation of microcytosis
Extensive and economical diagnosis and classification of hemoglobinopathies or thalassemia including complex disorders
Diagnosis of hereditary persistence of hemoglobin
Method Name
A short description of the method used to perform the test
Only orderable as part of a profile. For more information see THEV1 / Thalassemia and Hemoglobinopathy Evaluation, Blood and Serum.
Medical Interpretation
NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.
Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test
Aliases
Lists additional common names for a test, as an aid in searching
A2 Hemoglobin
Alpha Globin Variant
Alpha Thalassemia
Alpha-Thalassemia Evaluation
Barts Hemoglobin
Barts hydrops fetalis
Beta Globin Variant
Beta Thalassemia
E beta thalassemia
H Disease
Hb Barts
Hb H disease
HBA1
HBA2
HBB
HBG1
HBG2
Hemoglobin A2
Hemoglobin Cascade
Hemoglobin Electrophoresis
Hemoglobin Electrophoresis Cascade Level 1
Hemoglobin H disease
Hemoglobin Molecular studies
Hemoglobin Variant
Hemoglobinopathy
HGB (Hemoglobin) Electrophoresis
HPFH
Hydrops fetalis
Isoelectric Focusing
Mass Spectrometry
Microcytosis
MLPA
S beta thalassemia
Sickle cell
Sickling Test
Thalassemia
Specimen Type
Describes the specimen type validated for testing
Whole Blood EDTA
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 Type | Temperature | Time | Special Container |
|---|---|---|---|
| Whole Blood EDTA | Refrigerated | 7 days |
Useful For
Suggests clinical disorders or settings where the test may be helpful
Interpretation of results for the evaluation of thalassemias and hemoglobinopathies
Evaluation of microcytosis
Extensive and economical diagnosis and classification of hemoglobinopathies or thalassemia including complex disorders
Diagnosis of hereditary persistence of hemoglobin
Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
This consultative study is primarily designed for the evaluation of microcytosis but also can test for the detection of almost all known hemoglobin disorders in an economical manner. Because this can include multiple tests for alpha thalassemias, beta thalassemias, delta-beta thalassemia, hereditary persistence of fetal hemoglobin (HPFH), and for all known hemoglobin (Hb) variants, an expert in these disorders can guide testing to explain the clinical question or reported complete blood count values. This evaluation is particularly useful for complete classification of compound combinations of Hb S with alpha or beta thalassemia, Hb E/beta-0 thalassemia, and many other complex alpha and beta thalassemia disorders. Since iron deficiency can mimic thalassemias, if a serum sample is received, ferritin levels are measured to evaluate this possibility.
Hb disorders include those associated with thalassemias (decreased protein quantity) and Hb variants (abnormal protein production). Many are clinically harmless, while others cause symptoms including microcytosis, sickling disorders, hemolysis, erythrocytosis, cyanosis/hypoxia, long-standing or familial anemia, compensated or episodic anemia, and increased methemoglobin or sulfhemoglobin results. Hb disorders can show patterns of either autosomal recessive or autosomal dominant inheritance.
The thalassemias are a group of disorders of Hb synthesis. Normal adult Hb consists of 2 alpha globin chains (encoded by 2 pairs of alpha globin genes, each pair located on chromosome 16), and 2 beta globin chains (encoded by 2 beta globin genes, each located on chromosome 11). Thalassemia syndromes result from an underproduction of 1 or 2 types of globin chains and are characterized by the type (alpha, beta, delta, gamma), magnitude of underproduction (number of defective genes), and the severity of clinical symptoms (minor, intermedia, major). The severity of the clinical and hematologic effects is directly related to the imbalance of alpha-like to beta-like chains.
The most common form of thalassemia is alpha thalassemia. Alpha thalassemia usually involves deletion of entire alpha genes and varies in severity depending on the number of alpha chains deleted (or rendered nonfunctional). Alpha thalassemia trait usually results from the deletion of 2 alpha genes. The most common form of Hb H disease results from dysfunction of 3 alpha chains and shows a variable phenotype, with most cases showing moderate anemia. The deletion of all 4 alpha genes (Barts hydrops fetalis) is incompatible with life without significant medical intervention. Non-deletion alpha thalassemia genetic variants can also result in either thalassemia trait or Hb H disease and are less common than deletion forms.
Conversely most beta thalassemia genetic variants are due to single nucleotide substitutions that can occur anywhere in the beta globin gene. Large deletions of the beta globin gene complex can result in elevations in Hb F, such as HPFH or delta-beta thalassemia. While the presence of a single beta gene variant (beta thalassemia trait) results primarily in red blood cell microcytosis, cases with two beta gene abnormalities show a wide range in clinical severity, and many cases require molecular testing to understand the phenotype.
Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
Only orderable as part of a profile. For more information see THEV1 / Thalassemia and Hemoglobinopathy Evaluation, Blood and Serum.
Definitive results and an interpretive report will be provided.
Interpretation
Provides information to assist in interpretation of the test results
A hematopathologist expert in these disorders evaluates the case and an interpretive report is issued.
Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
No significant cautionary statements
Clinical Reference
Recommendations for in-depth reading of a clinical nature
1. Hoyer JD, Hoffman DR. The thalassemia and hemoglobinopathy syndromes. In: McClatchey KD, Amin HM, Curry JL, eds. Clinical Laboratory Medicine. 2nd ed. Lippencott Williams and Wilkins; 2002:866-892
2. Brancaleoni V, Di Pierro E, Motta I, Cappellini MD. Laboratory diagnosis of thalassemia. Int J Lab Hematol. 2016;38 (Suppl 1):32-40
3. Hartveld C. State of the art and new developments in molecular diagnostics for hemoglobinopathies in multiethnic societies. Int J Lab Hematol. 2013;36:1-12
Method Description
Describes how the test is performed and provides a method-specific reference
A hematopathologist expert in these disorders evaluates the case, appropriate tests are performed, and an interpretive report is issued.
PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information
Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.
Monday through Friday
Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.
Performing Laboratory Location
Indicates the location of the laboratory that performs the test
Fees :
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- Prospective clients should contact their account representative. For assistance, contact Customer Service.
Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.
Not Applicable
CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
CPT codes are provided by the performing laboratory.
CPT codes are provided by the performing laboratory.
83020-26
LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.
| Test Id | Test Order Name | Order LOINC Value |
|---|---|---|
| THEVI | Hemoglobinopathy Interpretation | 14869-2 |
| Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
|---|---|---|
| 608425 | Hemoglobinopathy Interpretation | 13514-5 |
| 608868 | Reviewed By | 18771-6 |