G6PD Blood Test | London Blood Tests UK

Check for G6PD deficiency with our blood test from £108. UKAS-accredited testing to assess haemolytic anaemia risk, fast results, optional GP review.

The Glucose-6-Phosphate Dehydrogenase (G6PD) Blood Test measures G6PD enzyme activity in red blood cells to identify G6PD deficiency, a genetic condition that can cause haemolytic anaemia when exposed to certain medications, foods, or infections. Priced at £108, analysed in a UKAS-accredited laboratory, with results typically available within 5–7 business days and an optional GP consultation for interpretation.

What is a G6PD Blood Test?

Glucose-6-phosphate dehydrogenase (G6PD) is an enzyme that protects red blood cells from oxidative damage. It plays a vital role in maintaining the integrity of red blood cells by helping neutralise harmful oxidative compounds.

G6PD deficiency is an inherited condition (X-linked) in which red blood cells lack sufficient protection against oxidative stress. When affected individuals are exposed to certain triggers — such as specific medications, infections, or foods like fava beans — red blood cells can break down prematurely, leading to haemolytic anaemia.

The G6PD Blood Test measures enzyme activity rather than genetic code, making it the preferred method for identifying functional deficiency. It is particularly important before prescribing medications known to trigger haemolysis and is commonly used in individuals from Mediterranean, African, Middle Eastern, and Asian backgrounds, where G6PD deficiency is more prevalent.

Benefits of the G6PD Blood Test

1. Identifies Risk of Haemolytic Anaemia
   Detects reduced enzyme activity that can cause red blood cell destruction when exposed to oxidative stress.

2. Essential Before Certain Medications
   Helps prevent adverse reactions to drugs such as some antibiotics, antimalarials, and sulfa-based medications.

3. Supports Safe Medical Treatment
   Enables clinicians to tailor prescriptions and avoid substances that may trigger haemolysis.

4. Diagnoses Unexplained Anaemia or Jaundice
   Useful when investigating episodes of fatigue, pallor, dark urine, or jaundice.

5. Relevant for Family and Ethnic Risk Screening
   Important for individuals with family history or from higher-risk ethnic backgrounds.

6. Non-Genetic Functional Assessment
   Measures actual enzyme activity, giving a real-world picture of red blood cell protection.

7. Optional GP Consultation for Guidance
   Results can be reviewed with a GP to discuss triggers, medication safety, and lifestyle precautions.

Why Do I Need a G6PD Blood Test?

You may benefit from G6PD testing if you:

• Have a family history of G6PD deficiency

• Experience unexplained episodes of anaemia or jaundice

• Develop symptoms after taking certain medications

• Are from an ethnic group with higher prevalence

• Are planning treatment with drugs known to affect red blood cells

• Have dark urine, fatigue, or shortness of breath after illness

Common symptoms of haemolysis include:

• Fatigue or weakness

• Pale or yellow skin (jaundice)

• Dark or tea-coloured urine

• Rapid heart rate

• Shortness of breath

Early diagnosis helps prevent avoidable haemolytic episodes.

How the Test Works

In-Clinic Blood Test

1. Book Your Appointment

   • Book online or by phone with no referral required.

2. Pre-Test Preparation

   • No fasting required.

   • Inform the clinician if you’ve recently had a haemolytic episode or blood transfusion.

3. Blood Sample Collection

   • A qualified phlebotomist collects a venous blood sample.

   • The process takes around 5–10 minutes.

4. Sample Handling

   • The sample is stabilised and transported under controlled conditions to a UKAS-accredited laboratory.

5. Laboratory Analysis

   • G6PD enzyme activity is measured using validated spectrophotometric methods.

6. Quality Control

   • Internal and external quality checks ensure accurate enzyme activity assessment.

7. Results Delivery

   • Results are typically available within 5–7 business days via secure online access.

8. Optional GP Consultation

   • A GP can review your results and advise on medication safety and lifestyle precautions.

At-Home Blood Draw (Home or Hotel Service)

1. Book a Home Visit

   • Choose a convenient UK-wide location and time.

2. Professional Phlebotomist Visit

   • A certified phlebotomist attends your home or hotel.

3. Blood Collection

   • A venous blood sample is collected safely and professionally.

4. Courier to Laboratory

   • The sample is transported the same day to the laboratory.

5. Analysis & Reporting

   • Enzyme activity is measured under UKAS-accredited standards.

6. Optional GP Review

   • Discuss results and next steps with a GP if required.

Your G6PD Test Results – Explained

G6PD results are reported as enzyme activity units (e.g., U/g Hb or U/10¹² RBCs), depending on the laboratory method.

Typical UK Reference Interpretation

• Normal activity: Adequate red blood cell protection

• Partial deficiency: Reduced enzyme activity; risk of haemolysis under stress

• Severe deficiency: High risk of haemolytic anaemia with oxidative triggers

Important Interpretation Notes

• Testing during or immediately after a haemolytic episode may give false-normal results due to young red blood cells having higher enzyme activity.

• Recent blood transfusion can also affect accuracy.

• Repeat testing may be advised if results are borderline.