<s>[INST] <<SYS>> This is a medical question of type : inheritance <</SYS>> Is juvenile idiopathic arthritis inherited ? [/INST] Most cases of juvenile idiopathic arthritis are sporadic, which means they occur in people with no history of the disorder in their family. A small percentage of cases of juvenile idiopathic arthritis have been reported to run in families, although the inheritance pattern of the condition is unclear. A sibling of a person with juvenile idiopathic arthritis has an estimated risk of developing the condition that is about 12 times that of the general population. </s>