The exact cause of the juvenile ankylosing spondylitis is unknown. The disease is strongly linked to a gene known as HLA-B27. Approximately 80-90% of children with JAS have the HLA-B27 gene.

These include sacroiliitis on imaging, especially in the presence of human leucocyte antigen B27 (HLA-B27). Rheumatologists face challenges when diagnosing axSpA, said Elaine Husni, MD ...