Mothers with HLA-B27 positive AS are more likely than HLA-B27 positive fathers with AS to get at least one child with axSpA*
| Number of parents with ≥1 Child with axSpA | Number of parents with no children with axSpA | Total | |
| Fathers | 14 (17.9%) (95% CI: 9.4% to 26.4%) | 64 (82.1%) (95% CI: 73.6 to 90.6) | 78 (100%) |
| Mothers | 9 (40.9%) (95% CI: 19.1% to 62.6%) | 13 (59.1%) (95% CI: 38.5 to 79.6) | 22 (100%) |
| Total | 23 | 77 | 100 |
| p=0.02 |
AS meeting the modified New York criteria.
*OR mothers/fathers 3.16 (95% CI 1.13 to 8.85
AS, ankylosing spondylitis; axSpA, axial spondyloarthritis.