Table 1.

Clinical characteristics of Taiwanese ankylosing spondylitis (AS) and normal controls.

Characteristics	AS Case	Normal
	N = 653	N = 952
Sex, N (%)
Male	535/653 (81.93%)	568/952 (59.66%)
Female	118/653 (18.07%)	384/952 (40.34%)
Age, Mean ± Std.	25.18 ± 9.27	47.98 ± 9.97
Syndesmophyte
None	345/653 (52.83%)
mSASSS * < 24	111/653 (17%)
mSASSS ≥ 24	197/653 (30.17%)
HLA-B27
Negative	52/653 (7.96%)
Positive	601/653 (92.04%)
Age onset group
≤16	94/653 (14.4%)
>16	559/653 (85.6%)

* mSASSS: modified Stoke’s Ankylosing Spondylitis Spinal Score.