Retinitis Pigmentosa is caused by a genetic defect. Less than 1% of the worlds population are carriers of the effected genes and only 1 in 3500-4000 people will develop RP. There are over 100 genetic mutations that have been found that cause RP so drilling down to each gene and how it manifests itself would be a bit more than I can handle. I’m not great when it comes to science at the best of times but I will explain here, to the best of my abilities, why genet are so important in RP and why we should at least understand the basics.
We inherit our genes from our parents and usually they make good and healthy humans, but sometimes things go wrong. In some instances of RP you inherit your genetic mutation from only one of your parents but in others, like mine, you must inherit the defective gene from both your parents. I have put together a bit of a chart explaining the genetic inheritance and patterns that can be found with each:
Autosomal Dominant RP:
- Usually shows up in the 40’s
- Only one parent effected by the disease
- Children have a 50% chance of developing RP
- 15-20% of RP’ers have this type
Autosomal Recessive RP:
- Usually shows up in the 20’s
- Both parents carry one copy of the mutated gene but don’t have RP themselves
- Children have a 25% chance of developing the disease
- 5-20% of RP’ers have this type including your trusty blogger
- Mothers are the carriers of the effected genes but usually don’t have RP themselves
- Sons have 50% chance of developing RP
- Daughters are usually just carriers but in rare cases may develop a mild form of RP
- 5-15% of RP’ers have this type
- There has been a lot of research with positive results in this type of RP
- Effects 40-50% of RP’ers
- Very rare
So why is all this important? Well, there are a lot of reasons. First of all, if you know what type of genetic inheritance you have you can understand when and how the disease will manifest itself. I don’t know about you but knowing that my clumsiness in my twenties has more to do with RP manifesting itself than the idea of having lost brain function was reassuring. Ok, so I’ve always been a little paranoid about losing my intelligence but when you don’t have much to lose….. Seriously though, knowing can be comforting. It also can help in decisions when it comes to having children, or if you were surprised by the disease after having your kids it can give you an idea of what their future may hold. Knowing that your children may have inherited a disease will help you guide them and give you a heads up if you notice they don’t seem to be seeing as well as they should be. It also helps those of us who are obsessed with a cure, to keep track of where the research is heading and how we can get involved and support our heroes, the researchers and yes, I am biased, I love a good team of RP researchers.
My next great feat is to convince you to go and get your DNA tested and submit your result to as many registries as you can. I will, however, put in one caveat to this. I have heard the attitude that until there is a cure, the person suffering from the disease just doesn’t want to know, and that’s ok. I would still encourage you to get the DNA tested and add it to the registries, you can always say no to any clinical trials, but the more information the researches have the closer we come to a cure, in my humble opinion. So, let’s talk about genetic testing. It is not painful in any way. A few vials of blood, ok so the pain of a needle, it’s not that bad and the results far outweigh the few seconds of a sore arm. In many cases the costs may be covered, you just need to ask your specialist and they can direct you to where you can apply. Remember, the information gained is vital to finding treatments and cures for this disease so it is important to at least ask your specialist, they won’t always volunteer the information.
Registering your genetic information is pretty straightforward, at least with your local registries, but to get your name in as many places as possible is also important. There aren’t a lot of us in the world with RP and there are so many different types and genes that are affected, well the more case studies researchers can access the better. I have included the links to as many registries as I could find and will add links as I find them. The other way to go is to send a letter or email with your information to research departments who are currently doing research and clinical trails into RP, usually at hospitals or universities. We are rare birds and if we want to encourage researchers to continue their work on our behalf, we must make the effort to get them the information and even test bodies they need. I know that my particular genetic defect is incredibly rare and that I am probably at the bottom of the pile for genes they may be able to treat, but, if my genetic material or letting an extra few people gaze into my eye helps the next person, then any suffering I may do was well worth it. So please, I implore you, please ask about genetic testing and get it done if you possibly can, the future is counting on you.