Frequently Asked Questions

Sickle cell disorder and thalassaemia are both inherited blood disorders where people are often treated with blood transfusions.

In sickle cell disorder, the red blood cells are often damaged and can then become stuck in blood vessels, causing pain and damaging organs. This can cause life-threatening complications such as stroke and severe breathing difficulties.

In thalassaemia, people cannot produce enough haemoglobin, causing severe anaemia, which can be fatal if not treated with blood transfusions.

Rare inherited anaemias include Diamond-Blackfan anaemia (DBA), congenital dyserythropoietic anaemias (CDA), congenital sideroblastic anaemias (CSA), and disorders of red cell membrane and enzymes, such as hereditary spherocytosis and pyruvate kinase deficiency (if transfusion dependent). These can be severe conditions and sometimes people need regular blood transfusions.

We are only offering testing in these disorders if patients need regular blood transfusions – there are about 200 patients in England who fit these criteria.

Although anyone can have these conditions, sickle cell disorder is more common in people of Black African or Caribbean heritage and thalassaemia is more common in people of Mediterranean, South Asian, Southeast Asian or Middle Eastern heritage. Sickle cell disorder affects about 17,000 patients in England with 250 new cases per year, and there are approximately 800 people with severe thalassemia, with about 50 new cases per year.

Red blood cells have labels on their surfaces, known as antigens or blood groups.

We inherit our blood groups from our parents and different people have different blood groups.

There are over 300 different blood groups, although the most important/well known ones are A, B and O, and RhD positive and RhD negative.

Blood is selected for transfusion
so the blood groups of the donor match those of the patient receiving the blood as closely as possible. This is known as blood matching.

Before a person receives a transfusion, they have a test in the hospital to check their basic blood groups. When the blood laboratory team choose blood for patients, they check that the blood group of the donors matches your blood groups as closely as possible.

No. There are over 300 blood groups. Hospitals will match for the most important blood groups. The most important ones are A, B, O and RhD. If you have sickle cell disease, thalassaemia or some rare inherited anaemias, they will match for more blood groups, usually C, c, E, e and K.

However, we do not currently have the ability to routinely match for all of the 300 blood groups – known as the extended blood groups.  A major reason for this is with our current technology.

As we don’t match for all the blood groups, transfused may contain blood groups present which the patient does not have. Most of the time, the patients’ immune system ignores this, but sometimes the immune system recognises the difference and makes an antibody against the blood group. This is known as a blood group antibody.

Having blood group antibodies means that it is harder to match blood and in some cases there is a delay in finding the blood for the patient. For some patients, blood can be found, but not enough blood.

As there are over 300 different blood groups we routinely select the most important blood groups to match, some of these are well known such as A,B,O. We also match for some additional blood groups for people with sickle cell and thalassaemia. But we do not match for all of them.

Having blood group antibodies means that it is harder to match blood and in some cases there is a delay in finding the blood for the patient. For some patients, blood can be found, but not enough. This means that patients can be under treated for their health conditions. 

We mostly do this using serology - by using antibodies to different blood groups in patients and donors. This is both time-consuming and expensive and we do not have the antibodies nor resources to test all the different blood groups of patients and donors. We do have some genetic testing available to patients (not donors) but this also does not test every blood group, is relatively slow, and not in routine use.

In 2014, a national audit undertaken by NHSBT showed that the extended blood groups were only known in 50% of patients with sickle cell disorder. This makes it harder to identify antibodies if they form them and also harder to find better matched units for transfusion.

If more patients and donors are tested for extended blood groups, it will be possible to ensure that transfused blood is more closely matched for the recipient, which will help stop antibodies forming. It will also make it easier to find compatible blood for people who already have antibodies.

This has already been shown to work in the Netherlands, where they have used this technology, to find matched blood for patients who previously could not have transfusions.

This technique also tests for different antigen types (called human leucocyte antigen - HLA), which may help people who need a bone marrow transplant find a matched donor.

Alongside the genetic blood grouping, the sample will be tested for the bone marrow type (human leucocyte antigen - HLA) as people may be eligible for stem cell / bone marrow transplant / gene therapy trials.

The first step would be to see if their sibling is a match.

Siblings will be tested by the normal routes and the tests offered on patients as part of this programme are screening tests.

If they show the possibility of matching more testing will need to take place.

Find more about the sickle cell disorder stem cell transplant programme.

For several years we have been able to test blood groups using genetics or DNA – known as blood group genotyping.

NHSBT, working with an international group of scientists and industry, has developed a more advanced method of blood group genotyping.

This newer blood group genotyping test can test for more blood groups than previous tests.

This may make it possible to test more patients and for the first time, blood donors.

Testing for bone marrow type (human leucocyte antigen - HLA) will also be offered as part of this programme.

Using donor and recipient genotyping data to support matching for extended blood groups will enable the NHS to provide the best possible blood for patients, reducing the risk of preventable complications.

For patients without antibodies it should be possible to identify better matched blood for transfusion and so reduce antibody formation.

For those that already have antibodies it should be easier and quicker to find blood for transfusion.

By also testing human leucocyte antigen (HLA), people who are potentially eligible for stem cell transplant will have taken the first step to see if they have a related HLA matched donor.

Yes. The patient or donor only requires a simple blood test, and they do not come into contact with the new machine.

We will be using a technology called array genotyping. This technology was based on the UK BioBank 2 array and has been developed by the Blood Transfusion Genomics Consortium, of which NHSBT is a member.

NHS England is funding NHSBT to provide the testing for the first year for patients in England.

This blood group genotyping test can be offered to all current patients with sickle cell, thalassaemia and transfusion dependent rare inherited anaemias free of charge to hospitals in England through the NHS within the 12-month programme.

For patients not tested in year one, we expect to offer the blood group genotyping test to these patients and new patients (circa 300 new-borns and importations) in future years. 

This programme is being delivered with the support of NHS England by NHSBT.

The testing in this first phase is being offered to people with sickle cell disorder, thalassaemia and transfusion dependent rare inherited anaemias for extended blood group testing and HLA testing only. Those with rare inherited anaemias will need to be transfusion-dependent to be eligible.

This programme complements a separate, existing programme in NHSBT to genotype a number of blood donors. Using donor and recipient genotyping data to support matching for extended blood groups will enable the NHS to provide the best possible blood for patients, reducing the risk of alloimmunisation and preventable complications. 

Approximately 80,000 donors will be genotyped by 2024 with an ongoing programme to genotype up to 500,000 donors in the next 3-5 years.    

No, this is not research. This is going to be offered as standard care, starting with the patients most affected by issues around blood matching – that is, people with sickle cell disorder, thalassaemia and those with transfusion dependent rare inherited anaemias.

Research may well be ongoing in your hospital as it is within the wider NHS. However, this blood group genotyping programme is not a research study, this is an improvement in clinical care, and it will be delivered by regular staff in your clinics, wards and laboratories working with NHSBT.

Research is vital in providing the evidence we need to transform services and improve outcomes, and this is particularly important for people with sickle cell disorder thalassaemia and rare anaemias. A lot of health research is carried out in the NHS, with recruitment and follow-up often taking place in clinical settings. 

You can find out more about research on the NHS England website.

Research may well be ongoing in the your hospital as it does frequently in the NHS. However, this is not a research study, this is an improvement in clinical care, and it will be delivered by regular staff in your clinics, wards and laboratories working with the national blood service for England known as NHS Blood and Transplant.

Research is vital in providing the evidence we need to transform services and improve outcomes, and this is particularly important for people with sickle cell, thalassaemia and rare anaemias, where historically little research has been done.

By fully integrating research into our organisation we can outperform organisations that do not, leading to better quality care and improved use of resources. A lot of health research is carried out in the NHS, with recruitment and follow-up often taking place in clinical settings.

You can find out more about research on the NHS England website.

The programme will be run within the NHSBT Genomics Programme governance structure.

An overarching programme steering group chaired by NHSE has been established which includes representatives from NHSE and NHSBT as well as professional bodies, stakeholders and Patient and Public Voice (PPV) representatives to provide direction to the programme development, oversight and review of progress. It reports into the NHS Medical Directorate and the NHS England National Healthcare Inequalities Improvement Board, as well as to the defined NHSBT governance structures.

We hope that NHSBT can start receiving samples by the autumn of 2023. The samples would be tested in batches several weeks later. We will confirm dates as soon as we can.

The testing is a simple blood test using DNA taken from the blood sample. The sample will go to the local transfusion laboratory, who will send it to NHSBT for testing. The patient does not need to be fasting and can be taken at any time.

We hope that eligible patients are offered this testing when they are having other blood tests e.g. when they come for an annual review or are admitted to hospital or seen in clinic. The test will be explained and the patient asked for consent. The sample form will include a tick box on consent which must be completed - the sample will not be processed without this box being ticked.

When testing begins, there will be patient information leaflets that patients can read to find out more.

The sample requirements will be exactly the same as for any blood grouping sample or transfusion specimen sent to NHSBT, except the NHS number will be a mandatory field.

Full details will be on the request form. 

Full sample requirements will be provided on the forms and on our IGBRL site.

Although the genetic testing does not require large amounts of blood, we want to make sure that for complex cases we have enough blood to do all the necessary testing.  

The samples will require: 

• 6mls EDTA for Adults/Adolescents 
• 2mls EDTA for Paediatric  
• 1-2ml EDTA for Under 6 months 

Testing will be performed in NHSBT laboratories, initially in Bristol.

NHS Blood and Transplant has developed a new form for this test. The form is available as a PDF on the IGBRL website, before the programme starts to allow hospitals to embed the ordering into their order comms system. This is available now.

An editable PDF will be available before sampling begins. 

Unlike previous NHSBT forms this will not be provided as a paper form but can be printed. 

Your hospital can explore creating their own form from their electronic ordering system. It will need to contain all the same information as the NHSBT form, laid out in the same way, but can be printed in black and white. It will need to accompany the sample.

We suggest that you make the mandatory fields electronically mandatory to decrease the chance of sample rejection.

Please discuss with us before making and using such a form, as it will need to be done in agreement with NHSBT.

Genetic testing of any sort requires consent. Clinical staff must obtain verbal consent and document this via a tick box on the sample form. The sample will not be processed without this box being ticked. 

Using established pathways, hospitals will send the samples to their local NHSBT Hospital Services who will forward them to the testing centre. All samples must be clearly addressed before sending, instructions will be provided.

The NHS Genomic Laboratory Hubs (GLHs) are not involved in this programme. All extended blood grouping in England, serological and genetic, is performed by NHSBT.

The NHS GLHs will continue to provide the specialist testing to make the diagnosis of these conditions for example for SCD, thalassaemia and rare anaemias. 

The testing will be done at NHSBT’s specialist Molecular Diagnostics laboratories in Bristol.

Local hospital transfusion laboratories will receive sample and send via routine NHSBT sample transport to their local NHSBT centre.

NHSBT will transport samlpes to Filton where they will be tested and if additional testing is required the IBGRL will undertake extended testing.

Turnaround time will be dependent on the number of samples being received as this is a high throughput batched test.

Once the process is established and sufficient samples are being received NHSBT will aim for a four week turn-around-time, if possible, for samples that do not require extended testing.

Sampling is expected to start in September and we hope testing will begin in October. If the test is urgent, existing pathways for extended blood group testing should be used.

The existing blood grouping tests at NHS Blood and Transplant will still be available and should be used where results are needed quickly.

Further details are available on the IGBRL pages.

These will continue to incur a cost to the hospital.

We do not anticipate we will be using this new technology for emergency testing.

Please see emergency testing information.

This will continue to be performed using the standard methods and a request must be made directly to NHSBT for this to be urgently undertaken if that is clinically indicated. This test will continue to incur a cost to the hospital.

Results will be available in the normal manner and will be presented in a similar way to other blood group tests.

Hospital and clinical laboratory teams will not need to interpret raw genetic data.

Any queries regarding results should be directed to NHSBT.

The results will be available on SpICE. 

Through your normal routes where results are accessed.

The results will be available on SpICE. E-mail reports will not normally be available

Clinical teams should share the results of the testing with the patients as appropriate.

It is essential that patient information is kept safe and secure. Results from this test will be treated in the same way as all samples sent to NHSBT; that is, blood samples tested by NHSBT are routinely available to the hospital that has sent your sample and can be viewed by other hospitals that the patient attends, so as to ensure the safety of any blood transfusion that they might have.

The genetic test will be limited to red cell antigens, and human leucocyte antigen only.

Send a sample again for this new test.