Fig 1. Description of the study design.

This schema of the study presents the 3 main steps of the analysis and, the resulting number of variants selected through each sub-analysis. (A) The selection of candidate variants was performed on the discovery set and resulted in the identification of 77 candidate SNVs (B) The association analysis was applied on the discovery set and 98 controls extracted from the 1000 genomes project. The 43 genes significantly associated with RA were re-tested after removing the candidate variant identified in step A and, the candidate variant was tested alone (C) The SNVs with the strongest RA association were re-sequenced in the extended families of the discovery, plus 9 new multiplex families.