PTPN22 and rheumatoid arthritis: Data from Problem 2 of the Genetic Analysis Workshop 15 (GAW15) were used to demonstrate meta-association testing of the PTPN22 candidate gene (14 single-nucleotide polymorphisms, or SNPs) and consensus criteria rheumatoid arthritis (RA) phenotype and sub-phenotypes in combined family-based and independent individuals using PedGenie 2.1.