Requesting genetic testing: A brief summary for all specialities
Checklist for offering Genomic testing
Is your patient eligible?
Check the Genomic test directory eligibility criteria.
Can I order the test?
What genes are tested?
Search for the testing code on PanelApp.
Has the patient given informed consent?
Do they understand the implications of the test for themselves and the family?
(see further details, below)
Have you documented informed consent?
A record of the discussion and consent should be documented in the notes, ideally with a record of whether the patient would share allow the sharing of information within the family.
Have you printed and completed the Genetic test request form?
Which sample do I need?
Usually EDTA sample, but check the sample requirements on the form.
Have you made a plan for return of results?
This is your responsibility as the clinician ordering the test.
What test can I do?
The NHS England National Genomic Test Directory lists:
- The indications for which genetic tests are available
- The eligibility criteria for each test
- Which specialties can order each test
You can check the test directory here: National Genomic Test Directories
If the patient is clinically affected and there is already a known pathogenic/likely pathogenic variant in the family, or if a family member has previously seen the genetics service, it is advised that the patient be discussed with Clinical Genetics prior to testing.
How do I send a sample for genetic testing?
Print and complete the test request form: Test Request Form
For most genetic tests the sample required is blood in EDTA, but see the sample requirements as specified on the form.
In most regions in Yorkshire, blood samples will be forwarded by your local pathology lab to the Genomics lab in Leeds. In some areas of East Yorkshire and Lincolnshire, alternative arrangements may need to be made locally. Please contact your local pathology service with any queries about sending samples to the Genomics laboratory. The laboratory address is on the referral form.
When do I mark a test as urgent?
Genetic test requests should only be marked as urgent if the results will:
- affect decisions in a current pregnancy
- influence time-critical management of an on-going diagnosis
- affect management of a neonate or paediatric patient
Which genes are tested?
PanelApp (https://nhsgms-panelapp.genomicsengland.co.uk/) is a platform for reaching consensus on gene panels within the NHS Genomic Medicine Service. Red (insufficient evidence, therefore probably won’t be tested), amber (moderate evidence, therefore may be tested) and green (high level of evidence, therefore will be tested) ratings are used to indicate the level of evidence for gene-disease associations.
Informed Consent - What do I need to include in the discussion?
A patient information booklet can be printed from: http://flipbooks.leedsth.nhs.uk/LN004517.pdf
This can help guide the consent process.
There are several key things to include in a discussion around genetic testing:
- How might results affect any treatment options?
- Could the test result tell the patient anything about future health risks?
- Is it possible that the test you have ordered could reveal information about another health condition not directly related to the reason for the test?
- Does the test need to be done now or can the patient consider having it done another time if they are unsure?
- How might the results affect other family members?
- Could this test affect life or critical insurance for the patient or their family?
- The possible test results (see below)
- A “normal” genetic test does not rule out a genetic diagnosis in the family. No genetic test can give a clean “genetic” bill of health.
- The possibility that the interpretation of the results may change over time (this is unlikely with a “pathogenic” variant).
- DNA will be stored in the genomics lab following testing and may be used to assist in other family testing or used for quality control purposes.
- For more information see: https://geneticalliance.org.uk/information/service-and-testing/benefits-and-risks-of-genetic-testing/
How do I record consent?
A record of the discussion and informed consent should be documented in the patient’s notes. As part of this, please ask the patient if they would consent to sharing information about their genetic testing result in order to help us advise their relatives.
How do I get the results:
The results will be returned to the referring consultant/clinician by post.
The time taken for the results to be returned can range from a few weeks for a single gene test to several months depending on test complexity and laboratory workload.
It is the responsibility of the referring clinician to communicate the results of the test to the patient. The results will not be routinely copied to Clinical Genetics and no action will be taken by the Clinical Genetics service unless the patient is referred to us.
What are the possible results?
There are three possible results for any diagnostic genetic test:
- “Pathogenic” or “likely pathogenic” variant(s) have been identified. It is important to read the interpretation of the result in detail so that you can advise your patient accordingly. This result often, though not always, means a diagnosis has been made.
- No variants identified. This does not rule out a genetic cause but makes it significantly less likely that any of the genes tested are involved. There may still be health risks to other family members. Other genomic testing (or research studies) may be possible in the future.
- “Variant(s) of uncertain significance” have been identified. These results cannot be used to guide management of the patient and, in most circumstances, testing will not be offered to other at-risk relatives.
In addition to the above results it is also possible, in some genetic tests (such as large panel, exome or whole genome sequencing), to obtain a result that suggests a diagnosis of a genetic condition that is seemingly unrelated to the reason that the testing was carried out. These results can be difficult to interpret at times and cause distress for the patient and their family.
When should I refer to Clinical Genetics?
We recommend referral to Clinical Genetics:
- For any patient in whom a genetic diagnosis is made
- For any patient in whom a “variant of uncertain significance” is found (as there may be further investigations that can be offered).
- If you are unsure whether the patient is eligible for genetic testing
- If the test the patient is eligible for is not open to anyone outside clinical genetics. If a non-genetics clinician orders a test that is open only to Clinical Genetics the laboratory will not perform the test. The sample will be stored.
- For any predictive testing (i.e. testing in an asymptomatic individual)
- If the patient wants a more in depth discussion before having testing. Please be aware that Clinical Genetics waiting lists mean that it will usually be up to 18 weeks before an outpatient appointment can be arranged.