Juvenile arthritis (JUVAR) is characterized by onset in early childhood of symmetric arthritis in multiple joints, associated with a marked increase in inflammatory markers. Some patients exhibit systemic symptoms, including quotidian fever, erythematous rash, generalized lymphadenopathy, hepatomegaly, and/or splenomegaly. There is high clinical variability, even within the same family (Karacan et al., 2018). [from
OMIM]