Our Target 5000 research project aims to provide genetic testing for the estimated 5,000 people in Ireland who have a genetic retinal condition. These conditions include, among others;
- Retinitis Pigmentosa (RP)
- Usher Syndrome
- Stargardt Disease
- Leber Hereditary Optic Neuropathy (LHON)
- Leber Congenital Amaurosis (LCA)
Why is genetic testing important for me?
Until now, one of the challenges confronted by someone who has one of these conditions was the lack of a precise diagnosis. It’s often impossible to tell which specific type of retinal disease a patient has based on just looking at the eye, because inherited retinal diseases are some of the most complicated of all genetic conditions, involving more than 200 genes. Receiving a complete diagnosis requires genetic testing. Through genetic screening of the person affected and their family members, Target 5000 will provide more detailed information about the nature and inheritance pattern of the condition.
How does it work?
The researchers will use DNA sequencing to try to find the gene that is mutated and causing the condition. This can be looked at like peeling an onion: First they look at the outside layer which contains the known genes associated with retinal degenerations. There are approximately 200 genes known so far, and these are estimated to account for conditions in about 60% of people affected. If your gene is in this first outside layer then finding the gene is relatively straightforward. However if the gene is not found in this outside layer then further work is needed to look at your entire genome. This will take a longer time, but the technology is constantly being refined and so this may happen sooner than we expect.
What happens when they find the gene mutation causing my condition?
When a causative mutation is discovered, you will be contacted by the hospital and an appointment will be set up so that you can receive the results of your genetic tests. Information about your gene and condition will then be added to a national patient registry. This registry will enable us to identify patients who are eligible for clinical trials. Research projects have now advanced through basic research to first stage clinical trials. Many of these therapies will rely on repairing the specific gene abnormality for each individual. That is why it is vital that we identify the exact genetic profile of people affected by a retinal degenerative condition in Ireland.
How can I get involved?
You can register for Target 5000 by contacting the Fighting Blindness research manager on 01 6789 004 or firstname.lastname@example.org. You will be asked to provide some basic information including personal details and details about your condition. This information is confidential and stored in a secure file accessed only by the research manager.
What happens next?
There are three sites involved in the Target 5000 project. They are based at the Royal Victoria Eye and Ear Hospital, Dublin, the Mater Hospital, Dublin, and the Royal Victoria Hospital in Belfast. The research teams will receive the requests for genetic sequencing from us and will call you when they have an upcoming clinic. When you attend your appointment, there are a couple of different things that will happen. The appointment may take up to three or four hours.
- You will be asked to sign a consent form indicating that you are a voluntary participant in the project.
- You will be asked some questions about your condition, including date of onset and type of symptoms.
- You will also be asked about any family history of sight loss and if any family members are affected by similar or other sight loss conditions. This information is hugely important so that clinicians can try to determine inheritance patterns of conditions.
- You will be asked to give a blood sample. The blood samples will be sent directly to Trinity College Dublin (TCD) and held securely. DNA will be extracted from the blood samples in TCD. A portion of the DNA sample is kept in secure storage in TCD, and a portion is sent for next generation sequencing to an accredited laboratory. A raw, DNA sequence file will then be sent back to TCD for analysis.
- The clinician will perform a series of visual tests. This is very important because as well as finding out the genetic cause of the condition, we also want to compare this with what your current vision is like. You will find a list of these tests on page 16 of this booklet.
How long will it take to get my results?
It is impossible to predict how long it will take to find your causative mutation as this will differ greatly from person to person, depending on the gene involved. When the research team finds your mutation, they will contact you to set up an appointment. The causative mutation will be added to the patient registry in order to match the clinical assessment data with a molecular diagnosis. This data may be used in the future to identify potential eligible participants for clinical trials.
If you have any questions about any of the information above or would like to find out more about the Target 5000 project, please contact the Fighting Blindness research manager on 01 6789 004 or email@example.com.