Gene testing anyone???

It seems there are a number of people who want to understand how and why they may want to get a genetic test for inherited retinal disorders. I recognize that members of the PRPH2 IC probably have already received a gene test but for the others, here are a few thoughts that might help you on your way.

1. Why get a gete test? At this time, there are very few solutions for people with RP so this will not help you “fix” your RP. However, there are two VERY important reasons to press on with the testing. First, if you are considering having children or if you already have children, it can be immensely informative. Secondly, the best chance of remediating an IRD rests with genetic science and research. Armed with your specific gene “defect”, you have an idea where to start looking or whether a specific bit of research is applicable to you. In other words, it is your starting point as we move into the brave new world of genetic medicine.

2. How do you get a test? The US and UK, gene tests are readily available at low or no cost. In the US, you need to work through your ophthalmologist. It is not clear to me that all ophthalmologists offer genetic testing. I would confirm with the doctor’s office before making the appointment that they offer genetic testing. In the end, it is at the discretion of the doctor as to whether you can have the test. If he/she deems it appropriate, they will take a blood sample or a cheek swab and send it for analysis. At this writing, the genetic tests evaluate more than 320 genes, looking for irregularities. The two companies that I am familiar with are Invitae and BluePrint Genetics. The latter provided my latest test results. This testing was funded by the Foundation Fighting Blindness through their program called MyRetinaTracker. I was very pleased with this program because they had a mandatory discussion with a genetics counselor (through a company called InformedDNA). Invitae offers genetics counseling but it is perhaps not mandatory. Please note that in the case of Invitae and BluePrint Genetics (via the FFB program), your ophthalmologist gets the test at no charge. This is not to say that the test is free because your ophthalmologist needs to gather the sample and perhaps even intervene to help you interpret the results (although, this latter may or may not be provided depending on your doctor).

3. What to do after the testing? So now that you have completed the testing and reviewed the results, it is perhaps not clear what is next. There are two steps (IMO). First, understand as well as you can your mutation and second, follow the research.

   1. Understand your mutation. Hopefully, the tests found what they believe to be your anomaly. I say this because in some cases, the results will be inconclusive or no anomalies found which can be frustrating. In your gene counseling, make sure you ask questions. This stuff is complicated but it is not unknowable. Keep in mind that as they talk about genes, you need to make a distinction between genetic inheritance and genetic expression. By this I mean, genes are passed through the generations in one manner and express themselves in another. For example, a recessive gene can express itself but not pass readily through the generations.

   2. Follow the research. In my opinion, this is the single most important result of genetic testing. At this writing, a tremendous amount of research is underway. The only way to assess its pertinence to you is to know your genetic mutation. A number of patients assume their doctor will help them with understanding the current research. THIS IS A FALLACY. Your eye doctor looks at the health of your eye and likely performs various FDA approved procedures. He/she does NOT necessarily follow or study research or clinical trials. This is our collective responsibility. One exception is that in some geographies, you may have access to an MD/PhD who is involved in research at the university level. In that case, it is likely your doc has some exposure to the research world (although, in many cases, they only have visibility to their little part of the research world)- It is an exciting and fascinating time. Stay positive.