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Frequently asked questions

Who do I ask if I want a genetic test?

Speak to your GP, or ophthalmologist if you have one; they will be able to make the appropriate referrals. See Getting a referral. Your current ophthalmologist may be able to arrange the test themselves.

How old do you have to be to get a genetic test?

Any child or adult who has signs or symptoms of an inherited sight loss condition can get a genetic test, no matter what their age. Predictive testing and carrier testing is usually only offered to adults unless the family condition is one that can start in childhood. See Genetic testing.

Is a genetic test free, or will I have to pay?

In the UK, genetic testing is available for free on the NHS when arranged by an ophthalmology or genetics specialist doctor. See Getting a referral. Private ophthalmology clinics can also arrange genetic testing.

Will I have to wait a long time to get a genetic test?

There is likely to be a waiting list for appointments at a specialist ophthalmic genetics clinic or at your regional clinical genetics service, but this will vary by clinic. Ask your GP or ophthalmologist if they can give an idea of waiting times. If your current ophthalmologist can get the testing process started themselves, then this may happen more quickly.

If I have a test will I definitely find out my causative gene?

No. For around 25 – 30% of people living with an inherited retinal condition, a genetic test will fail to return a result. This is because some causative genes are yet to be discovered, while others aren’t fully understood. See Genetic testing.

What is whole genome sequencing?

You may have heard your genetic counsellor or ophthalmologist mention that your genetic test will involve whole genome sequencing (WGS). This is a new type of test that was introduced by the NHS in early 2022 and is now used for all inherited retinal dystrophy genetic testing. Whole genome sequencing still only requires a small sample of blood, but is more in-depth than the old style test and examines sections of genetic code that were previously ignored. It is therefore more likely to identify the genetic change that is causing the condition, but this is still not guaranteed. Your ophthalmologist or genetic counsellor will go through a detailed consent form with you before you have the test and you will be able to ask any questions about the process. The consent form for WGS also gives you the option of allowing your sample to be included in future research studies.

How quickly will I get the result?

Unlike more routine blood tests, the result of a genetic test can sometimes take several months to come through. This is because of the specialist nature of the test. Ask your ophthalmologist or genetic counsellor how long they expect your result to take.

Does knowing my gene mean I am more likely to access a therapy or treatment?

Possibly. Many of the treatments currently being developed are designed to target specific genetic faults, and a genetic test result would be essential to confirm if you were eligible to receive or take part in a clinical trial of such a treatment.

For many genes, there is no gene-specific treatment in development. However, researchers are working on non gene-specific treatments too, and may prefer to know your genetic diagnosis if you are considering taking part in a clinical trial of one of these, because it helps them learn more from the trial. See Genetic testing.

I would not be interested in receiving any kind of therapy or treatment. Is it still worth me getting a test?

There are still reasons to consider getting a test. The result can confirm your family’s inheritance pattern and open up choices for you or your close relatives, as well as provide a more precise diagnosis that may be helpful for you and your ophthalmologist. A genetic counsellor can help you decide whether or not to have testing. See Genetic testing and Genetic counselling.

I was diagnosed many years ago, and just told I had retinitis pigmentosa (RP). Is it still possible for me to get a genetic test?

Yes. Anyone with a diagnosis of an inherited sight loss condition can have a test. Researchers have learned a huge amount about RP genes over the last 10 to 20 years, and testing has improved considerably. Speak to your GP or ophthalmologist if you would like a referral for testing. See Getting a referral.

I have been told I have retinitis pigmentosa (RP). Do I still need a test?

RP can be caused by any one of a considerable number of genes and can be passed down through a family in different ways; see Inheritance patterns. A genetic test result can provide you and your ophthalmologist with more precise information, confirm the inheritance pattern, and open up choices for you and your family. See Genetic testing . A genetic counsellor can help you decide whether or not to have testing. See Genetic counselling.

Who can help me understand the impact of a genetic diagnosis on my wider family?

Genetic counsellors are specially trained healthcare professionals who can spend time with you discussing the wider implications of a genetic test result. Your GP or ophthalmologist can refer you for genetic counselling. See Genetic counselling and Getting a referral. Your ophthalmologist themselves may also be able to help.

I’m a bit worried about getting a test and can’t decide if I want one. Is there anyone I can talk to about this?

Genetic counsellors are specially trained healthcare professionals who can talk through your concerns and help you reach a decision that is right for you. They will not put you under any pressure to have a test. Your GP or ophthalmologist can refer you for genetic counselling. See Genetic counselling and Getting a referral.

If I have a genetic diagnosis, do others in my family still need a test? Or can we assume it’s the same causative gene?

Close relatives who are also living with sight loss are very likely to have the same genetic fault, but it is worth them considering their own test to confirm. A confirmed result will be necessary if they want to access gene-specific treatments or clinical trials, or certain options around family planning. They can discuss testing with their ophthalmologist or a genetic counsellor.

Close relatives with no symptoms will need to undergo predictive or carrier testing if they want to find out if they have inherited the genetic fault. Genetic counsellors are best placed to discuss these options with family members. It will be helpful for your relatives and their genetic counsellor if you can provide as much information as possible about your genetic test result. See Genetic counselling and Genetic testing.

How can I get involved in research?

One way to register your interest in taking part in research-related activities is to join the Retina UK research panel. We are often approached by researchers and the pharmaceutical industry for help in recruiting people living with inherited sight loss for various activities, including online surveys, telephone interviews or focus groups. Very occasionally, we are asked to help recruit for clinical trials. To find out more, please contact

It is also worth making your ophthalmologist aware that you are interested in taking part in research, and asking if your clinic holds its own research participation register.

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