Please login to post a response.

• how is it possible
• Posted: 2008-04-08 15:05:15 By Robert W
• I have been diagnosed with RP. The only person in my family that has this condition is a third cousin. Can anybody explain to me how i inherted this. No one else in my family has this but her. and i am very confused on this condition.
  
  Thank you

• Re: how is it possible
• Posted: 2008-04-08 15:19:08 By Darran Z
• Is it the same gene responsible? That is the first question that needs to be answered.
  
  There are two scenerios.
  
  1. It is an autosomal receissive form (same gene responsible for both your RP) that happened to be passed down along the same ancestory you are related to. When paired again with another recessive gene mutation, viola! RP! I know that may be difficult to comprehend without a picture but I don't know exactly the family lines that link you and your cousin together.
  
  2. A new RP was formulated somewhere in the process and you both will have different genes responsible for RP.
  
  I suggest you read the publication"Inheritance Patterns of retinal degeneration" on the FFB and Google inheritance patterns in general to understand how the basics work. There are some very rare and complexities but understanding the basics is the foundation of understanding the complexities.
  
  Darran

• Re: how is it possible
• Posted: 2008-04-08 23:41:21 By Patrick C
• I know how you feel. Me, and one of my brothers both have it. I have 3 siblings. Nobody in our family has ever had anything like this. I've wondered so much how me and my brother both could have this when there is no history what so ever of eye problems in my family.

• Re: Re: how is it possible
• Posted: 2008-04-09 10:11:40 By Darran Z
• Patrick,
  
  If you and your brother have it, it would be the same gene responsible. You would likely have the autosomal recessive inheritance pattern. Which means both of your parents were carriers of the RP gene. Not affected because they had one normal gene paired with it (we inherit two genes--one from each parent). You and yoru brother were the lucky dogs to get both recessive genes.
  
  Now as to your children, they will not have RP but be carriers of the RP gene. So no worries about your children being affected.
  
  Darran

• Re: Re: Re: how is it possible
• Posted: 2008-04-10 14:57:35 By Patrick C
• Darren, thanks for the info. Yep, we're real lucky! haha It **** how things work that way. Nobody in the family ever having it, then BAM, me and my brother have it. But, I guess it happens huh?
  
  What if the mother of my child is a carrier? Since I have it, am I still a carrier? Or do I just pass on the carrier gene?

• Re: Re: Re: Re: how is it possible
• Posted: 2008-04-10 18:49:31 By Darran Z
• Patrick,
  
  The odds of you and your spouse/partner of having the exact same gene is very slim. You will always pass on the RP gene to your children. I have not seen a case reported in the autosomal recessive form that would pass it along to their children. That's a very very slim chance, next to zero. You both would have to have the same gene mutation.
  
  If they were different RP genes, you will have a Non-RP child from what I understand. I could be wrong but that's the way I've understood it.
  
  Darran

• Re: Re: how is it possible
• Posted: 2008-04-15 19:28:47 By Carol C
• Patrick,my brother has XLRP ( cone-rod dystrophy), and if we didn't know a lot of extended relatives, we would think his came out of the blue because no one in our line has had it since a g-g- uncle, although numerous 3rd and 4th cousins are effected. Most people don't know their g-g- uncles and 3rd and 4th cousins. 5 generations of women passed down the gene without having an effected son, until Paul.My mother's sisiter eventually went blind,was told it was lazy eye and "retinal" degneration, but she had the exact symptoms as my brother, so was likely a manifesting carrier( no bio kids).Your gene could be recessive, but more and more isolated male cases are being exposed as X-linked. It could be recessive, but if it's X-linked, the good news is most mutations causing this seem to lie on the RPGR gene, which can now be closely examined, and the exact mutation identified. It took 3 months for a lab to identify my brother's mutation, and now all relatives can have the test to determine carrier status or if a male will develop it. If you have contact with a genetic clinic, they can help you get this done. Carol

• Re: Re: Re: how is it possible
• Posted: 2008-04-17 15:18:11 By Marisa P
• Patrick,
  
  You are like most of us...surprised and wondering where it came from. In my family two out of three siblings have Usher (RP and hearing loss). I just say we won the lotto without even playing. :) My brother has children and grandchildren and none seem to have been affected. Of course the grandchildren are young still.

• Re: Re: Re: Re: how is it possible
• Posted: 2008-04-18 13:10:48 By Robert W
• I read on a website that RP is not always hereditary. It can cause by Viral Infection or some such thing. Any yall heard of that before.

• Re: Re: Re: Re: Re: how is it possible
• Posted: 2008-04-20 18:45:23 By Marisa P
• RP is definitely genetic. What I think it's interesting is how it presents itself at different times in life, even within the same family. (I know what you are going to say, Darran :) )