here's another picture

another view

We need some closeups of the aberrant growth.

RRD growth on some roses is pale rather than purple, so don't rule is out on those grounds.

After getting some sharp pictures, I would go ahead and take out that cane down to the ground and bag it. Any chance of herbicide exposure? It's probably not that, since the offending cane is high and to the back..

I had Alba semi-plena and it's growth after spring bloom never looked that way.

I agree with Michael about looking closer. Especially, put new leaves beside the older ( better looking leaves) and see if the edges have the same pattern, also the stipules).
Also measure the distances between leaves as they go out a cane, not at the base , but starting six inches out.

Another question, is this rose against a wall that gets hit by prevailing winds in early fall?

thank you for your responses, here are somemore pictures, this one shows the aberrant growth next to normal growth.

here is a normal branch also yesterday there was a half open bloom in the strange growth and this rose never blooms this late.

all the strange growth is a pale lime green and wrinkly as compared to the alba gray green leaves which are more oval and smoother.

I hope these pictures are better,
Michaelg there hasn't been any herbicide exposure
but, Ann in answer to your question, this rose is on an East wall of the house with exposure to strong south winds. The highway and fields are to the south and we are in the middle of multiflora country. I live in a rural area of Central Ohio with mutiflora rose everywhere. I try to get it out of my tree lines but it pops up again and again.
roseberri

I think it's probably RRD and you should remove and bag the plant, but Ann is the expert, so you might wait for her to weigh in.

Is it all on one cane? If so I suggest removing just the cane with the odd growth at ground level. You could then try spraying the rest of the bush with commercial 3% hydrogen peroxide and/or putting aspirin tablets near the roots to try to booster the plants immune system against virus infections.

FOR ASPIRIN:
http://forums2.gardenweb.com/forums/load/roses/msg0610421011109.html

AND FOR hydrogen peroxide:

http://forums2.gardenweb.com/forums/load/roses/msg0417381111236.html

Here is a link that might be useful: first link aspirin and roses

Unfortunately it is on over half the plant! I don't know how I could have missed it ! I did make a cutting two years ago for my cousin(actually I took a lot of them when I was pruning it). The cutting was very delicate and took a long time to take and was the only one to work. Is it likely that it will be infected too? I still have it in a pot and it looks normal right now.
roseberri

By the way, this rose is too large to bag first, do I spray it with hairspray and then cut it into baggable pieces? Can I burn it?
roseberri

you can chop it up (just make sure to sterilize your pruners afterwards). I had to do that with my Reve d'Or this past weekend. Took two big black trash bags.