How whole genome sequencing works

On this page, we have information about how whole genome sequencing works, and what the process would look like.

Whole genome sequencing process

1. The process will start by your doctor offering you whole genome sequencing (WGS) as part of the NHS Genomic Medicine Service.
2. If you consent, a doctor will take:
   • a blood sample – which shows DNA information inherited from parents. This is called a ‘germline’ sample.
   • a small piece of cancer or tumour tissue – which shows the DNA information of the cancer or tumour. This is called a ‘somatic’ sample.
3. The samples will be collected and transported to a genetic laboratory for testing.
4. Your healthcare professional will talk to you about the WGS test and what it could mean for you and your family. They will record this discussion on a ‘record of discussion’ form. They’ll also share a copy of the form with you.
5. Your healthcare professional will also speak to you about the opportunity to contribute to a National Genomic Test Directory.
6. The results will be returned to your healthcare professional, who will talk to you about the results and what they mean for you.

Genome sequencing results

• No relevant findings – This means that at the time of reporting, researchers have not found a genomic reason to explain your sarcoma. In the future, as knowledge and technology improves, they may be able to find the cause. Your medical team may advise you on whether you should seek further advice (for example, if there is a change in your condition, or if someone in the family is planning a pregnancy).

• Relevant finding – This means that researchers have found a genomic reason to explain your sarcoma. The finding might influence your treatment. It might also inform your family members of their risk of having the same condition.

• Uncertain finding – This is a change that could explain your sarcoma. However, you may need to undergo more tests to determine if the change is relevant. This might include testing other family members. In some cases, it’s unclear whether the change is the cause of sarcoma or just part of a normal gene variation. This might become clearer with time and as our knowledge of the genome improves.

Part 4
Advantages and disadvantages