Autoimmune. Jra (also called jia) for juvenille idiopathic arthritis is a disease of unknown etiology. Joint deformity and dysfunction can result from the damage caused by the dysfunctional immune system rheumatologists can provide appropriate diagnosis and treatment which often entails immune suppressants.
Depends upon control. Jra starts as inflammation in joints. This then can lead to damage of the supporting ligaments which in turn then can lead to altered joint forces and deformity. Medical control of the jra now often prevents such progression.