HLA-DRB1 and juvenile ankylosing spondylitis: The HLA-DRB1*04 has been linked to systemic arthritis [3, 32] and the HLAB27 have long been recognised as a contributing factor to the development of enthesitis related arthritis; moreover, this allele seems to be related to axial inflammation with hip involvement and subsequent juvenile ankylosing spondylitis [3, 4, 26, 33, 34].