Hemoglobinopathy Evaluation

The Hemoglobinopathy Evaluation test contains 1 test with 14 biomarkers.

Brief Description: The Hemoglobinopathy Evaluation test is a specialized laboratory assay designed to identify and characterize abnormal hemoglobin variants in the blood. Hemoglobinopathies are genetic disorders that result from alterations in the structure or production of hemoglobin molecules, leading to conditions such as sickle cell disease and thalassemia.

NOTE: Only measurable biomarkers will be reported. Certain biomarkers do not appear in healthy individuals. 

Also Known As: Hemoglobin Evaluation Test, Hb ELP Test, Hb IEF, Sickle Cell Screen Test, Hemoglobin Fraction Test, Hemoglobinopathies Test

Collection Method: Blood Draw

Specimen Type: Whole Blood

Test Preparation: No preparation required

When is a Hemoglobinopathy Evaluation test ordered?

Hemoglobinopathies must be tested for as part of the state-mandated newborn screening program. Additionally, when a parent is at high risk or when parents have a kid with hemoglobinopathy, it is frequently utilized for prenatal screening.

When a complete blood count and/or blood smear reveal that a person may have an atypical form of hemoglobin, an assessment is typically requested.

It might be prescribed if a medical professional believes that a patient's signs and symptoms are brought on by irregular hemoglobin production. Hemolytic anemia is frequently brought on by abnormal types of hemoglobin and is characterized by symptoms like:

• weakness, exhaustion
• Not enough energy
• Jaundice
• light skin

A few severe hemoglobinopathies can cause episodes of excruciating pain, shortness of breath, an enlarged spleen, and issues with a child's growth.

What does a Hemoglobinopathy Evaluation blood test check for?

An individual with a hemoglobinopathy has an inherited blood ailment in which their hemoglobin is produced at a reduced rate or in an aberrant form. The goal of a hemoglobinopathy evaluation is to screen for and/or diagnose a hemoglobin disease by identifying aberrant forms of or indicating issues with hemoglobin production.

All red blood cells include hemoglobin, an iron-containing protein that binds to oxygen in the lungs and enables RBCs to transport the oxygen throughout the body, supplying it to the body's cells and tissues. Heme, the molecule with iron at its center, makes up one portion of hemoglobin. The other portion is made up of four globin chains. The globin chains are referred to as alpha, beta, gamma, and delta depending on their structural makeup. The functions of hemoglobin and its capacity to carry oxygen depend on the kinds of globin chains that are present.

Types of normal hemoglobin include:

• About 95%–98% of the hemoglobin (Hb) found in adults is hemoglobin A, which has two alpha and two beta protein chains.
• About 2%–3% of adult hemoglobin is hemoglobin A2, which has two alpha and two delta protein chains.
• In adults, hemoglobin F, which contains two alpha and two gamma protein chains, accounts for 1% to 2% of all hemoglobin. The fetus produces the majority of this hemoglobin during pregnancy; production typically declines after birth and approaches adult levels in 1-2 years.

When the genes that produce the globin chains mutate, it results in hemoglobinopathies, which modify the proteins. One of the typical globin chains may produce less as a result of these genetic modifications, or they may produce globin chains with different structural characteristics. The behavior, stability, production rate, and/or structure of hemoglobin can all be impacted by genetic changes. Red blood cells' appearance and functionality can be changed by the presence of aberrant hemoglobin within them.

Hemolytic anemia is caused by red blood cells with defective hemoglobin, which may not transport oxygen effectively and may be broken down by the body earlier than usual. The three most prevalent hemoglobin variants are hemoglobin C, which can cause a slight amount of hemolytic anemia, hemoglobin E, which may or may not cause any symptoms, and hemoglobin S, which is the primary hemoglobin in people with sickle cell disease and causes the RBC to become misshapen and reduce the cell's survival.

A gene mutation causes diminished synthesis of one of the globin chains, which leads in the disorder known as thalassemia. This may throw off the ratio of alpha to beta chains, leading to the formation of aberrant hemoglobin or an increase in minor hemoglobin components like Hb A2 or Hb F.

There are many more uncommon variations of hemoglobin. Some have no visible signs or symptoms, while others have an impact on the stability and/or performance of the hemoglobin molecule. The types and levels of hemoglobin present in a person's sample of blood are often assessed during an assessment of a hemoglobin problem. Several instances include:

• Tests for hemoglobin S, the primary hemoglobin associated with sickle cell disease, are performed using the hemoglobin solubility method.
• Blood-hematology electrophoresis
• High performance liquid chromatography for isoelectric focusing of hemoglobin

Lab tests often ordered with Hemoglobinopathy Evaluation test:

When a Hemoglobinopathy Evaluation is ordered, it's typically part of a broader assessment of hemoglobin disorders and their impact on health. Here are some tests commonly ordered alongside it:

1. Complete Blood Count (CBC) with Differential:

   • Purpose: To evaluate overall blood health, including red and white blood cells, hemoglobin, hematocrit, and platelets.
   • Why Is It Ordered: To assess for anemia and other blood cell abnormalities that are common in hemoglobinopathies.

2. Reticulocyte Count:

   • Purpose: To count the number of young red blood cells (reticulocytes) in the blood.
   • Why Is It Ordered: To evaluate the bone marrow's response to anemia; a high reticulocyte count can indicate increased red blood cell production, which is often seen in hemolytic anemias.

3. Iron Studies (Serum Iron, Ferritin, Total Iron-Binding Capacity [TIBC], Transferrin Saturation):

   • Purpose: To assess iron status.
   • Why Is It Ordered: To rule out iron deficiency as a cause of anemia and to monitor for iron overload, a possible complication of frequent blood transfusions in hemoglobinopathy patients.

4. Bilirubin, Lactate Dehydrogenase (LDH), and Haptoglobin:

   • Purpose: To assess for hemolysis (destruction of red blood cells).
   • Why Is It Ordered: To monitor for hemolytic anemia, a common complication in many hemoglobinopathies.

These tests, when ordered alongside a Hemoglobinopathy Evaluation, provide a comprehensive assessment of hemoglobin disorders. They are crucial for accurately diagnosing the specific type of hemoglobinopathy, assessing its severity, monitoring for complications, and guiding appropriate management. The specific combination of tests will depend on the individual’s symptoms, clinical presentation, and family history.

Conditions where a Hemoglobinopathy Evaluation test is recommended:

The Hemoglobinopathy Evaluation test is essential for diagnosing and monitoring various conditions, including:

1. Sickle Cell Disease: This genetic disorder results from a mutation in the beta-globin gene, leading to the production of abnormal hemoglobin (hemoglobin S) and causing red blood cells to become misshapen.

2. Thalassemia: Thalassemias are a group of genetic disorders characterized by reduced production of one or more globin chains of hemoglobin, leading to anemia and related complications.

How does my health care provider use a Hemoglobinopathy Evaluation test?

The protein found in all red blood cells that carries oxygen is called hemoglobin, and a hemoglobinopathy examination is used to find aberrant types and/or relative levels of it. Tests might be conducted for:

Screening

Newborns must be checked in every state for specific hemoglobin variations.

High-risk parents with an ethnic origin linked to a higher prevalence of hemoglobin abnormalities and those with affected family members frequently undergo prenatal screening. Prior to becoming pregnant, screening may be done in addition to genetic counseling to ascertain whether the parents are carriers.

To find variations among asymptomatic parents with an ill child

Diagnosis

To find and/or identify hemoglobinopathy in those who have unexplained anemic symptoms or abnormal complete blood count results

A person's hemoglobin type can be determined using a variety of laboratory techniques. A few of these are:

• Tests for hemoglobin S, the primary hemoglobin associated with sickle cell disease, are performed using the hemoglobin solubility method.
• Blood-hematology electrophoresis
• Isoelectric focusing of hemoglobin
• High performance liquid chromatography of hemoglobin

Based on the physical and chemical characteristics of the various hemoglobin molecules, these approaches assess the various hemoglobin subtypes.

One of these tests, or a combination of them, can be used to diagnose the majority of common hemoglobin variations or thalassemias. Any observed variant hemoglobin's relative concentrations can help with a diagnosis. However, it is typically insufficient to diagnose hemoglobinopathy with a single test. Instead, the outcomes of numerous tests are taken into account. Other possible laboratory examinations include, for instance:

• CBC Reticulocyte count Blood smear
• Studies on iron using transferrin, TIBC, and serum iron

Genetic testing: can be used to find changes in the genes that produce the chains of proteins that make up hemoglobin. This is not a common test, but it can be used to determine if a person has one or two copies of a mutant gene.

What do my Hemoglobinopathy Evaluation test results mean?

When evaluating the findings of an assessment for hemoglobinopathy, care must be exercised. The laboratory report typically comes with an interpretation from a pathologist with knowledge in hematology.

The types and relative amounts of hemoglobin present are often reported in the evaluation's findings. The percentages of adults' normal hemoglobins are as follows:

• Hemoglobin A: between 95% and 98%
• Hemoglobin A2: between 2% and 3%
• 2% or less for hemoglobin F

Testing may be used to identify a disorder that results in the production of hemoglobin with structural changes or a condition known as thalassemia, where a gene mutation reduces the production of one of the globin chains. This may throw off the ratio of alpha to beta chains, leading to the formation of aberrant hemoglobin or an increase in minor hemoglobin components like Hb A2 or Hb F.

These tests can measure and detect some of the most prevalent types of aberrant hemoglobin, including:

The main hemoglobin in persons with sickle cell disease is hemoglobin S. According to the Centers for Disease Control and Prevention, around 1 in 500 African American infants are born with this ailment, and more than 70,000 Americans currently have it. The proportion of Hb S in sickle cell disease patients is high. In spite of having a modest amount of Hb S, people with sickle cell trait nonetheless have the regular type of Hb A. When exposed to low oxygen levels, Hb S makes red blood cells distorted. Red blood cells with scleroderma can obstruct small blood vessels, resulting in discomfort, poor circulation, decreased oxygen delivery to tissues and cells, and reduced cell survival. High levels of hemoglobin A or F can keep red blood cells well-oxygenated and prevent sickling.

Hemoglobin C: Approximately 2 to 3 percent of people of African origin have the hemoglobin C trait. Hemoglobin C disease is uncommon and often not severe. It typically results in a mild to moderate spleen enlargement and a little amount of hemolytic anemia.

One of the most prevalent beta chain hemoglobin variants in the world is hemoglobin E. It is especially common among people with Southeast Asian ancestry. Homozygous carriers of Hb E typically have mild hemolytic anemia, microcytic red blood cells, and a minor splenic enlargement. Unless another mutation is present, a single copy of the hemoglobin E gene does not cause symptoms.

The main hemoglobin that a growing fetus produces is hemoglobin F. Normal Hb F production starts to decline after birth and reaches adult levels between the ages of 1-2. In many diseases, including beta thalassemia and sickle cell anemia, Hb F may be high.

In a few instances of alpha thalassemia, hemoglobin H is present. It is created because there is a severe lack of alpha chains and is made up of four beta globin chains. The four beta chains do not function appropriately even though each beta globin chain is healthy.

Babies with alpha thalassemia develop hemoglobin Barts, a particular type. When there are not enough alpha chains, it is made of four gamma protein chains, much as how Hb H is made. Due to declining gamma chain synthesis, Hb Barts vanishes quickly after delivery.

Additional types that could be found include:

• hematoxylin D
• Blood globin G
• hematoxylin J
• hematoxylin M

Spring Constant Hemoglobin

Additionally, a person can receive two distinct defective genes from each parent. Compound heterozygosity or doubly heterozygosity are terms used to describe this. Hemoglobin SC illness, sickle cell - hemoglobin D disease, hemoglobin E - beta thalassemia, and hemoglobin S - beta thalassemia are a few examples of clinically relevant combos. See the articles on Thalassemia and Hemoglobin Abnormalities for more information on this.

Most Common Questions about the Hemoglobinopathy Evaluation test:

Purpose and Indications for the Hemoglobinopathy Evaluation Test

Why is the Hemoglobinopathy Evaluation test ordered?

The Hemoglobinopathy Evaluation test is primarily ordered to diagnose and differentiate various types of hemoglobinopathies, which are genetic disorders affecting the structure or production of the hemoglobin molecule in red blood cells.

Who should get a Hemoglobinopathy Evaluation test?

People with a family history of hemoglobinopathy, those displaying symptoms of anemia not explained by other causes, or individuals from ethnic groups with higher prevalence rates (such as African, Mediterranean, or Southeast Asian heritage) might be advised to undergo this test.

Clinical Significance of Test Results

What do abnormal results in the Hemoglobinopathy Evaluation test suggest?

Abnormal results can indicate the presence of a hemoglobinopathy like sickle cell anemia, thalassemia, or other rare hemoglobin variants. The specific type and its severity can often be discerned from the pattern of results.

Can the Hemoglobinopathy Evaluation test distinguish between different types of hemoglobinopathies?

Yes, the test can differentiate between various hemoglobinopathies. Different hemoglobin variants migrate differently on electrophoresis, helping in their identification.

Interpretation and Follow-up

If the Hemoglobinopathy Evaluation test shows abnormal hemoglobins, what steps should one take next?

Further confirmatory tests, such as genetic testing, might be required. A hematologist or genetic counselor can provide guidance on treatment options, management, and potential implications for family members.

How often should individuals with diagnosed hemoglobinopathies undergo this test?

The frequency varies based on the specific condition and its severity. Some patients might need periodic monitoring, while others, once diagnosed, may not need frequent re-evaluation unless new clinical issues arise.

Conditions and Medications Influencing the Test

Do conditions like iron-deficiency anemia influence Hemoglobinopathy Evaluation test results?

Yes, iron-deficiency anemia can affect the synthesis of hemoglobin chains, which might complicate the interpretation of the test. It's essential to consider such co-existing conditions when interpreting results.

Do medications interfere with Hemoglobinopathy Evaluation test outcomes?

Some medications may cause temporary changes in the red blood cells or hemoglobin, which could influence the test results. It's crucial to inform the healthcare provider of any medications being taken before the test.

Dietary Influence and Recommendations

Can dietary habits influence the Hemoglobinopathy Evaluation test results?

Generally, diet does not directly influence the structure or variants of hemoglobin. However, a diet leading to conditions like iron-deficiency can indirectly affect the test's interpretation.

Is there a need for any dietary restrictions before taking the Hemoglobinopathy Evaluation test?

No specific dietary restrictions are required before the test, but it's always recommended to follow any instructions provided by the healthcare provider.

We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.