What is genetic testing?
Genetic testing can offer an explanation for why you have a certain illness. Scientists can look at your genes in detail to see if you have a genetic condition causing your high cholesterol, including familial hypercholesterolaemia (FH).
The results make it easier to:
- make a diagnosis
- find the right treatment
- find others in your family with the same condition.
What does genetic testing involve?
To have a genetic test, you will need to give a sample of blood or tissue. The sample will be sent to a laboratory so that your genes can be looked at in detail to see if you have a faulty (altered) gene which can cause high cholesterol.
Genetics testing can be organised by your specialist doctor at a lipid clinic. It’s not yet available everywhere in the UK, so your specialist will let you know if they think you should have it and if it’s available in your area.
Getting your results
If you are the first person in your family to have a genetic test, it can take some time to get your results – around two or three months or sometimes longer. It’s a complicated test and the scientists need to search for all the possible genes that could be causing a problem, so it can take time to find the gene or parts of the gene involved.
Sometimes a faulty gene can’t be found. Genetic testing can find a faulty gene in about three out of every four people with FH.
If your test finds a faulty gene
If your test finds the gene which is causing your high cholesterol, your specialist will tell you more about:
- what condition you have
- how it affects your cholesterol levels
- the best treatments for you
- how they can keep an eye on your health.
Your specialist might also ask for your help in finding other close members of your family with the same condition – this is called cascade testing.
Finding a variant of unknown significance (VUS)
Sometimes a gene will be found that looks different to how it’s expected to, but it’s not clear whether it’s harmless or disease-causing. This is called a variant of unknown significance, or VUS.
Your specialist will talk to you about what this means for you. They might also want to test other members of your family to find out more.
If your test doesn’t find a faulty gene
If no faults or alterations can be found, it could mean that:
- you don’t have a genetic condition
- you do have a fault in a gene which is known to cause disease but it couldn’t be found – some genetic alterations are very difficult to find
- you have a fault in a gene that causes disease, but it hasn’t been identified yet.
Your specialist will talk to you about what it means if no genetic cause for your high cholesterol can be found, and how you can bring it under control.
What happens to your sample?
Your specialist should tell you what will happen to your sample. It will be routinely stored in case it’s needed at a later date. Improvements in technology may mean that further tests can be done in the future.
Before you have a genetic test, you should have genetic counselling. This could be with an FH professional such as your doctor or nurse, or it could be with a genetics counsellor at a specialist clinic. They can help you to understand:
- what happens when you have a genetic test
- what the results might mean for you and your family
- how having FH or another condition may affect you
- how having FH or another condition might affect any children you have, now or in the future.
You can speak to your health professional about any practical concerns you have too. For example, whether the results could affect life or travel insurance, job applications and mortgage applications, and what you can do about this.
Should you have a genetic test?
You don’t have to have a genetic test if you don’t want to, it’s a very personal choice.
Before you decide if it’s right for you, talk to your health professional or genetics counsellor about what’s involved and any worries you might have. They can help you weigh up the pros and cons and what the results could mean for you and your family.
Waiting for and getting results can be a stressful time, and some people feel anxious or even guilty, but on the other hand you might feel relieved when you get your results. There are many good points about getting a test:
- it can give or confirm a diagnosis
- you can start treatment quickly
- your health can be monitored
- your future risk of illness could be lowered
- if a gene is found, your family can get tested too.
If you have a genetic condition, testing family members helps to find other people with the same condition before it causes a problem.
If you have genetic testing and a faulty gene is found, your doctor will suggest that your family members have a test too, as it’s likely that some of them will have the same condition. Likewise, you may be contacted if someone in your family has been diagnosed with a genetic condition.
Most people with FH, for example, have two close relatives with FH – a brother, sister, parent or child.
It’s much easier to find a faulty gene in other family members once it's been found in one person. The geneticists already know what they’re looking for and don’t need to search all the genes that can cause disease. This is called cascade testing.
Why is it good for family members to be tested?
Sometimes people have a genetic condition such as FH and don't know it because they don’t have any related health problems such as heart disease, perhaps because they have a very healthy lifestyle. It’s even possible to have a genetic condition and not have high cholesterol. They could still pass the gene onto their children, who could go on to have high cholesterol and health problems.
Finding out if someone has a condition means their whole family, including children, can get treatment if they need it.
Telling your family you have a genetic condition
If you have FH or another condition, it’s likely that your doctor will want your help to contact your family. They might give you a letter to pass on which explains about the condition, the health problems it can cause, and how the genetic test works. Passing on this letter can help prevent heart disease and stroke in your family for generations to come.
Some people find it hard to explain to their family what their condition is and why it’s important to get a test. You might not be in touch with some family members or might not be on good terms, which can make contacting them or talking to them difficult.
If you would like any support in contacting or talking to your family, our specialist nurses or your genetics counsellor may be able to help.
How will getting a genetic test affect your insurance?
If you have a diagnosis of a long term inherited condition, such as FH, your life insurance could cost more.
If your condition is being properly managed, the diagnosis does not necessarily mean you are ‘high risk’ for an insurer or mortgage lender. You could ask your health professional for a supporting letter to support your application.
At the moment, there is a temporary agreement in place which stops insurance companies from asking about the results of genetic testing. But you do have to disclose a family history of serious inherited disorders, and many insurance companies will 'load' your insurance fee as a result.
Find out more
- Find out more about insurance for people with serious health conditions by contacting the Association of British Insurers (ABI).
- You can also find more information from The ABI Code on Genetic testing and Insurance.
- Genetic Alliance have some very helpful frequently asked questions and answers about genetic conditions and insurance.
You can also contact an insurance broker. They are professional insurance experts who can help find different types of insurance and suitable policies for people who may have had issues finding insurance: British Insurance Brokers Association
Genetic testing for FH is available on the NHS throughout England. It's provided through the NHS Genomic Medicine Service, as outlined in the National Genomic Test Directory.
Testing is provided by the national genomic testing network of seven Genomic Laboratory Hubs (GLHs). Each GLH works with the lipid clinics or specialist centres in their region to communicate the local pathways in place.
To access this testing, GPs and other healthcare professionals should refer eligible patients with a possible or probable diagnosis of FH to a specialist with expertise in FH to confirm the diagnosis and start family cascade testing as appropriate. If local lipid clinics or specialist centres require further information about the arrangements for genomic testing within their region, they should contact their local GLH.
Further information about the NHS GMS can be found on the NHS website.
For any patients/clinicians in the East Midlands/East of England who have any questions about the genomics service visit this site.
FH genetic testing in Scotland is available for all patients who meet the Simon Broome or Dutch criteria, with testing done in Aberdeen. Most of the requests come from secondary care lipid clinic specialists and their teams, but appropriate requests are accepted from GPs, Cardiology, paediatricians, metabolic doctors and other relevant specialists. The route for people in Scotland is to ask their GP to refer them to their local lipid clinic for evaluation.
FH genetic testing has been routinely offered since 2010 and is funded entirely by central commissioning following agreement from the Welsh Government. Most tests are facilitated by a lipid clinic with triage referrals direct to the FH nurse if appropriate. All requests require a clinical proforma, documented consent and inclusion of the 'phenotype score'.
If the score is 6 or over and the information is complete the lab will process these. If this is not met, then the request is sent to the FH service medical lead for review.
In practice, nearly all requests are made by an FH nurse. The FH nurse will see patients virtually, in primary or secondary care and occasionally at home. This process does take some time and most clinicians would ask the FH nurse to carry out testing.
Testing for FH in Northern Ireland is available for all patients who score 6 or above using a locally modified version of the (Dutch/Welsh phenotype criteria), or at the request of a relevant consultant.
The majority of requests come from clinicians at lipid or metabolic clinics, but referral pathways also exist for GPs, Cardiac Rehabilitation clinics, and Outreach projects (such as "Farm Families"), much of which is in collaboration with the FH Nurse team. Cascade/family testing is primarily via the FH nurses.
Update on FH and the Armed Forces
There has been a recent change in policy for people with FH who wish to join the armed forces. Now, those with FH / who have previously had high cholesterol levels and are being treated with cholesterol-lowering medication such as a statin will be referred to SSMES and then reviewed by either a cardiologist or lipid specialist as required. Those who are taking a statin should have a stable medication history for 6 months. They should also have a normal exercise tolerance whilst completing exercise which is compatible with military training requirements for at least the last 3 months without symptoms (such as unusual muscle pain or fatigue). If acceptable for entry they are FIT with an E2 marker for annual medical review.
This information applies to all armed forces but it should be noted that it does not guarantee acceptance, as deployment can be limited by medical treatment needs, and certain roles require people to be 'medically fully deployable'. People who have uncontrolled/untreated high cholesterol levels will still be considered unfit for duty/entry into the forces due to their increased risk of morbidity associated with their condition i.e. premature coronary heart disease.