Juvenile idiopathic arthritis (JIA) is considered to be a multifactorial disease caused by a combination of environmental factors and predisposing genetic factors. Twins studies found a strong heritability (strong genetic factors) but genetic studies such association studies of large cohorts of patient (GWAS or Genome Wide Association Study) have elucidated less than 20 % of the genetic basis of JIA. The vision of the genetics of multifactorial diseases has recently changed revealing a large clinical and genetic heterogeneity of these diseases. Indeed, the advent of next-generation sequencing identified non-multifactorial genetic hereditary disease related to mutations in genes having strong effect on the onset of the disease without real impact of environmental factors among the so called "multifactorial diseases" (Parkinson's, diabetes, osteoarthritis, Alzheimer's, hypertension ...)The investigators propose to study 30 families with several forms of JIA by next-generation sequencing. Identifying the genetic basis of JIA in these families will help to better understand the physiopathology of this disease and may help to the identification of novel therapeutic targets for other patients with JIA.

Inclusion Criteria:

• AJI oligoarticular form <4 joints
• AJI Polyarticular form> 4 joints
• AJI Forms systemic arthritis
• duration For more than six weeks
• Onset of symptoms before the age of 16 years
• Or rheumatoid factor or ANA + or CCP +Acceptation of both parenth to participate to the research and to perfom blood samples for genetic studies

Exclusion Criteria:

• The (the) patient (e) is under tutorship or curatorship
• The (the) patient (e) is under judicial protection
• The (the) patient (e), or his parents, refuses to sign the consent
• It is impossible to give (the) patient (e) information lit
• JIA spondyloarthropathies such
• JIA type psoriatic arthritis or enthesopathy
• JIA not classifiable