Genotype Blood Test

The Genotype Blood Test is a comprehensive haemoglobinopathy screening panel that assesses your blood count, haemoglobin fractions and sickle cell status. It can help identify inherited haemoglobin variants and traits associated with conditions such as sickle cell disease and thalassaemia. The test is available for £160, with testing at various UK locations, at-home phlebotomy and an optional GP consultation.

What is a Genotype Blood Test?

A Genotype Blood Test examines blood count and haemoglobin characteristics to identify patterns that may indicate an inherited haemoglobin variant. The panel includes haemoglobin electrophoresis, Haemoglobin A2, Haemoglobin F and a sickle cell screen, alongside a full blood count.

Haemoglobin is the protein in red blood cells responsible for carrying oxygen around the body. Genetic changes affecting haemoglobin can result in different haemoglobin variants or changes in how much of particular haemoglobin types are produced. Some people are healthy carriers of an inherited trait and may have few or no symptoms, while others can inherit combinations of variants that cause a haemoglobin disorder.

The test can therefore be particularly useful when there is a family history of sickle cell disease, thalassaemia or another haemoglobin disorder, when someone comes from a population in which these conditions are more prevalent, or when a blood count suggests possible microcytosis or another unexplained red-cell abnormality.

What Does the Genotype Blood Test Include?

The panel includes:

Haemoglobin Analysis

• Haemoglobin A2
• Haemoglobin F
• Haemoglobin Electrophoresis
• Sickle Cell Screen – Solubility Test

Full Blood Count

• Haemoglobin
• Red Blood Count
• Haematocrit (HCT)
• MCV
• MCH
• MCHC
• RDW
• Platelets
• MPV
• White Cell Count
• Neutrophils
• Lymphocytes
• Monocytes
• Eosinophils
• Basophils

Blood Group

• Blood Group

The combination of haemoglobin analysis and red-cell indices can provide considerably more information than a standard blood count alone.

Benefits of the Genotype Blood Test

1. Screens for inherited haemoglobin variants

The test can identify patterns associated with inherited haemoglobin variants. Haemoglobin electrophoresis separates different haemoglobin fractions, allowing a laboratory to assess whether an unusual haemoglobin pattern is present.

2. Helps assess sickle cell status

The included sickle cell solubility test can screen for the presence of sickling haemoglobin. Where a positive or abnormal screening result is obtained, additional laboratory investigation may be required to establish the specific haemoglobin pattern.

3. Helps investigate thalassaemia traits

Haemoglobin A2 and red-cell indices such as MCV and MCH can provide important clues when assessing possible beta-thalassaemia trait. A low MCV or MCH does not automatically mean thalassaemia, but the pattern may prompt further investigation.

4. Provides a detailed haemoglobin profile

Haemoglobin electrophoresis provides information about the different haemoglobin fractions present in the blood. HbA2 and HbF are particularly useful when assessing certain inherited haemoglobin conditions.

5. Investigates unexplained red-cell abnormalities

The full blood count provides measurements of haemoglobin, red-cell number, cell size and haemoglobin content. Abnormal MCV, MCH, RDW or haemoglobin levels can provide useful information when investigating anaemia or other blood abnormalities.

6. Supports family planning and reproductive discussions

Knowing whether you carry an inherited haemoglobin trait can be particularly important when planning a family. If both biological parents carry certain haemoglobin variants, there can be a risk of a child inheriting a clinically significant haemoglobin disorder. A GP or specialist genetic service can provide appropriate counselling where required.

7. Useful when there is a family history

If a close relative has sickle cell disease, thalassaemia or another inherited haemoglobin disorder, testing can help determine whether you have a relevant haemoglobin pattern or carrier state.

8. Helps clarify microcytosis

A low MCV can occur with iron deficiency as well as thalassaemia traits and other conditions. Looking at the red-cell indices together with haemoglobin fractions can help a clinician decide whether further testing is appropriate.

9. Provides a useful baseline

For people who have never had haemoglobinopathy screening, the results can establish a baseline that may be useful for future medical assessments, particularly before pregnancy or when investigating unexplained blood-count abnormalities.

10. Optional GP consultation

An optional GP consultation allows your results to be discussed in context. If an abnormal haemoglobin pattern is identified, a GP can explain what it may mean and advise whether additional testing, specialist referral or genetic counselling is appropriate.

Why Do I Need a Genotype Blood Test?

You may consider this test if you have a family history of sickle cell disease, thalassaemia or another inherited blood disorder.

It may also be relevant if:

• You have unexplained anaemia
• Your MCV or MCH is persistently low
• You have previously been told you may carry a thalassaemia trait
• A family member has sickle cell disease or sickle cell trait
• You are planning a pregnancy
• Your partner has a known haemoglobin variant
• You come from a population where haemoglobin disorders are more common
• You have previously had an abnormal haemoglobin electrophoresis result
• You want to investigate an unexplained red-cell abnormality
• You need haemoglobinopathy screening for personal or family reasons

Possible symptoms

Many people who carry a haemoglobin trait have no symptoms at all. Symptoms associated with clinically significant haemoglobin disorders can vary considerably.

Possible symptoms may include:

• Persistent tiredness
• Reduced exercise tolerance
• Shortness of breath
• Pale skin
• Dizziness
• Recurrent episodes of unexplained anaemia
• Unexplained jaundice
• Episodes of severe pain in people with certain sickling disorders

Symptoms alone cannot determine whether someone carries a haemoglobin variant. Laboratory testing is required.

Step-by-Step: How the Genotype Test Works

In-Clinic Testing

1. Book your appointment

Choose an available appointment at one of our UK locations. The Genotype Blood Test is available for £160.

2. Review your preparation

The test generally does not require fasting. Follow any specific preparation instructions provided with your appointment.

3. Attend the clinic

Your details and requested tests are confirmed before the sample is collected.

4. Venous blood collection

A trained phlebotomist takes a blood sample from your arm using sterile, single-use equipment. The procedure usually takes only a few minutes.

5. Full blood count analysis

The laboratory assesses your red and white blood cells, haemoglobin, haematocrit, MCV, MCH, MCHC, RDW and platelets. These measurements provide important information about the size, number and characteristics of your blood cells.

6. Haemoglobin electrophoresis

The laboratory analyses the different haemoglobin fractions in your blood. This can identify patterns that may be consistent with certain inherited haemoglobin variants.

7. HbA2 and HbF assessment

Haemoglobin A2 and Haemoglobin F are measured as part of the haemoglobin analysis. Their proportions can provide additional information when investigating conditions such as beta-thalassaemia and other haemoglobin disorders.

8. Sickle cell screening

The sickle cell solubility test is performed as part of the panel. If the screening result is positive or otherwise requires clarification, additional testing may be recommended to identify the specific haemoglobin variant.

9. Results report

Your results are compiled into a laboratory report showing your numerical blood-count results and haemoglobin findings, together with the applicable reference ranges.

10. Optional GP consultation

A GP consultation is optional. If your results indicate a possible haemoglobin variant or carrier state, a GP can explain the findings and advise whether further investigation or specialist haemoglobinopathy testing is appropriate.

At-Home Blood Draw – Home or Hotel

1. Book your home appointment

Arrange an appointment for a professional phlebotomist to visit your home or hotel.

2. Prepare for your appointment

Follow the preparation instructions provided. Fasting is generally not required for this type of blood test unless other tests are being performed at the same time.

3. Professional phlebotomist visit

A trained phlebotomist arrives at your chosen location with the equipment required for the blood draw.

4. Blood sample collection

A venous blood sample is collected using sterile, single-use equipment. The procedure is the same type of blood draw performed in a clinic.

5. Sample identification and handling

Your samples are labelled and prepared for laboratory transportation according to the appropriate sample-handling requirements.

6. Full blood count

The laboratory measures your red and white blood cell parameters, including haemoglobin, RBC count, MCV, MCH, MCHC, RDW and platelet count.

7. Haemoglobin analysis

Haemoglobin electrophoresis and the relevant haemoglobin measurements are performed to assess the proportions and patterns of haemoglobin present.

8. Sickle cell screening

The sickle cell solubility screen is performed. If further clarification is required, your clinician may recommend additional haemoglobin analysis or genetic testing.

9. Receive your results

Your completed report is provided securely once laboratory analysis is complete.

10. Optional GP consultation

You can arrange an optional GP consultation to discuss your findings and whether further testing or specialist assessment may be appropriate.

Your Genotype Blood Test Results – Explained

The results contain several different measurements, so interpretation depends on the overall pattern rather than one number alone.

Haemoglobin

Haemoglobin is commonly reported in g/L.

A typical adult male reference range may be approximately 130–180 g/L, while an adult female range may be approximately 115–165 g/L, although the exact range depends on the laboratory.

Low haemoglobin can indicate anaemia, while an elevated result can have several possible causes.

MCV

MCV measures the average size of your red blood cells and is reported in fL.

A commonly used adult reference interval is approximately:

• Normal: 80–100 fL
• Low: below 80 fL
• High: above 100 fL

A low MCV can occur with iron deficiency or thalassaemia trait, among other causes.

MCH

MCH measures the average amount of haemoglobin in each red blood cell.

A commonly used range is approximately 27–33 pg per cell, although your laboratory's reference interval should be used.

Low MCH can occur with iron deficiency and some haemoglobin disorders.

MCHC

MCHC describes the concentration of haemoglobin within red blood cells.

A typical reference range is approximately 320–360 g/L, although laboratory ranges differ.

RDW

RDW measures variation in red blood cell size.

A commonly used range is approximately 11.5–14.5%.

An increased RDW can occur in several types of anaemia and may provide additional context alongside MCV and other blood results.

Haemoglobin A2

HbA2 is one of the haemoglobin fractions measured during haemoglobin analysis.

A typical adult HbA2 percentage is approximately 2.0–3.5%. A persistently elevated HbA2 can be associated with beta-thalassaemia trait, although interpretation depends on the complete haemoglobin profile and clinical context.

Haemoglobin F

HbF is the predominant haemoglobin during fetal development and normally represents only a small proportion of haemoglobin in healthy adults.

Adult HbF is commonly less than 1%, although reference limits vary. Increased HbF can occur in several inherited haemoglobin conditions and should be interpreted by an appropriately qualified professional.

Sickle Cell Screen

The sickle cell solubility test is generally reported as a screening result such as:

• Negative: no sickling haemoglobin detected by the screening method
• Positive: sickling haemoglobin may be present and further testing is required

A positive solubility test does not distinguish between sickle cell trait and sickle cell disease and does not identify every possible haemoglobin variant. Additional haemoglobin analysis or molecular testing may therefore be required.

Blood Group

Your blood group identifies your ABO group and RhD status, for example:

• A positive
• A negative
• B positive
• B negative
• AB positive
• AB negative
• O positive
• O negative

Blood group is an inherited characteristic and is particularly important in certain medical and pregnancy-related circumstances.