Question
I have RA. Can you tell me the likelyhood that my identical twin sister will develope RA in her life time? How much of a role is genes in RA?
Answer
The chance of an identical twin developing RA if the other twin has RA (the genetic term is called the concordance rate) is about 30-50%. Thus although genes are important, they are not the only factor needed for the development of RA.
