By both congenic mapping in inbred strains and SNP typing in wild rats, we identified a conserved, 33-kb large haplotype Ltab-Ncr3 in the MHC-III region, which regulates the onset, severity, and chronicity of arthritis.
Patients who carried the HLA-Cw*06 allele had a significantly earlier mean age of onset of both psoriasis (P = 0.01) and arthritis (P = 0.008) compared with Cw*06-negative patients.