What is the common age for the onset of rheumatoid arthritis and is there a genetic component?
Although RA can start at any age, it most commonly starts in the 40 to 50 age range. The second part of your question is complicated and would take a textbook to answer fully. There is likely a genetic comnponent. Patients with a genetic marker DR4 have more severe RA, if they get RA. If you have a first degree relative with RA you have a slightly increased risk of getting RA– in most studies a 1.5 to 3 times greater risk. However in terms of statistics, the added risk is still low and it points to the fact that it is not genetics alone but likely also an environmental factor as well.