Table 6.

Proband’s New York radiographic and HLA-B27 status and proband’s gender strongly affect likelihood of axSpA among offspring

AxSpA among offspring	Proband			P value
	Father	Mother
Children of	axSpA child/all children	axSpA child/all children	OR (95% CI)
All probands	16/144 (11.1%)	13/61 (21.3%)*	2.17 (0.71 to 4.84)	0.056
HLA-B27(+) probands	15/132 (11.4%)	13/42 (31.0%)	3.50 (1.50 to 8.15)	0.0026
HLA-B27(−) probands	1/12 (8.3%)	0/12 (0%)	–	0.31
New York(+) AS probands	15/119 (12.6%)	12/29 (41.4%)	4.89 (1.96 to 12.23)	0.00032
New York(−) nr-axSpA probands	1/25 (4%)	1/25 (4%)
New York(+) and HLA-B27(+) AS probands	15/119 (12.6%)	12/29 (41.4%)	4.89 (1.96 to 12.23)	0.00032
New York(+) and HLA-B27(−) AS probands	–	–	–	–
New York(−) and HLA-B27(+) nr-axSpA probands	0/13 (0%)	1/13 (7.7%)	–	0.31
New York(−) and HLA-B27(−) nr-axSpA probands	1/12 (8.3%)	0/12 (0%)	–	0.31
Sons of	axSpA sons/all sons	axSpA sons/all sons
HLA-B27(+) probands	5/62 (8.1%)	5/14 (35.7%)	6.33 (1.52 to 26.33)	0.0057
HLA-B27(−) probands	1/7 (14.3%)	0/5 (0%)	–	0.38
New York(+) and HLA-B27(+) AS probands	5/53 (9.4%)	4/11 (36.4%)	5.49 (1.18 to 25.47)	0.019
New York(+) and HLA-B27(−) AS probands	–	–	–	–
New York(−) and HLA-B27(+) nr-axSpA probands	0/9 (0%)	1/3 (33.3%)	–	0.07
New York(−) and HLA-B27(−) nr-axSpA probands	1/7 (14.3%)	0/5 (0%)	–	0.38
Daughters of	axSpA daughters/all daughters	axSpA daughters/all daughters
HLA-B27(+) probands	10/70 (14.3%)	8/28 (28.6%)	2.40 (0.83 to 6.92)	0.10
New York(+) and HLA-B27(+) AS probands	10/66 (15.2%)	8/18 (44.4 %)	4.48 (1.42 to 14.12)	0.0073

OR: Ratio of odds of children with axSpA from mother with AS and odds of children with axSpA from father with AS.

*HLA-B27 of seven children unknown.

AS, ankylosing spondylitis; axSpA, axial spondyloarthritis; nr-axSpA, non-radiographic axial spondyloarthritis.