Does anyone know anything about retina pigmentosa?

[CrazyPlateLady]

My cousin has it. His brother is being tested for it and their other brother won't get tested even though his eyesight is truely appalling.

My nan said that only the women in the family are carriers but only the men get it, As this is my dads side, I thought that I couldn't be a carrier, but my nan gets info wrong, quite a lot. She said its what my aunt told her but I have been reading on the net and I can't see how they know this as they haven't had any genetic testing done, as far as I know.

My nan did tell me that my aunt was getting tested to see if she was a carrier. This was a while ago and I just asked her about it and she said she didn't know if my aunt was being tested, she can't rememeber.

I can't phone my aunt as relations with us are strained so can't speak to her about it. The cousin who has it and the brother being tested have different dads so it is likely to have come from my aunt.

DS is having his eyes tested next month due to a possible problem with his left eye (nothing to do with RP) but I am now worrying that I could too be a carrier and he could end up with RP and I would be devastated for him.

I am probably worrying for nothing but I don't really understand all the technical stuff on the net so was wondering if anyone here has any experience or knowledge of it.

Hi,
If your dad is not suffering from it, I think your ds should be ok. You- and he- might still be carriers though.

RP can be inherited in many different ways. One of them is the way your nan is talking about. This is recessive X-linked inheritance: the disease would be on the X-chromosome, and only comes to light when you have just the mutated copy. This way all men with the mutation will get the disease (as thye have only one X), while the women will be carriers (as they have two Xs and therefore one healthy chromosome). This means basically that your dad would have to have RP if it has come down his family, for you to be a carrier.

As I said there are many ways to inherit RP. In all of these however, as long as both your dad and you are symptom/disease free, your son should be fine, and at most be a carrier.

Thanks. I did manage to find a website that explained it so I could actually understand it.

From what I have read, it sounds like the X linked one in our family which means that I can't have got it from my dad and I won't be a carrier either. Only women are the carriers.

If it was because of the recessive gene, then there would be more cause for concern as there would be a 1 in 4 chance of any of us being carriers. As my 2 cousins have different dads though, I'm hoping that it would just be a very unfortunate coincidence that they were both recessive gene carriers. Its not great for my cousins as they all have high chances of either having it or passing on the gene and as 1 in particular won't face up to it, there is no way of knowing if he has it, his future DDs would definitely be carriers.