RT Journal Article SR Electronic T1 Spinal ankylosing spondylitis: a variant form of ankylosing spondylitis or a distinct disease entity? JF Annals of the Rheumatic Diseases JO Ann Rheum Dis FD BMJ Publishing Group Ltd and European League Against Rheumatism SP 368 OP 371 DO 10.1136/ard.44.6.368 VO 44 IS 6 A1 J T Gran A1 G Husby A1 M Hordvik YR 1985 UL http://ard.bmj.com/content/44/6/368.abstract AB In a population survey of ankylosing spondylitis (AS) seven subjects, six males and one female, had x-ray changes in the lumbar spine typical of AS but without concomitant roentgenological sacroiliitis. The overall prevalence of such cases in the population studied was 0.37%. Four out of these seven subjects carried the tissue antigen HLA-B27 (57%). The clinical and roentgenological features of these subjects are described and it is suggested that the x-ray findings represent a mild and variant form of primary or definite AS.