Case–control association between children carrying one or two risk alleles and allele-positive mothers’ rheumatoid arthritis status
| Risk allele group | n Proportion of allele-positive mothers with allele-positive children | RA (mother) OR (95% CI)* | p Value | |
| Cases | Controls | |||
| HLA-DRB1 | ||||
| Shared epitope + | 122/139 | 242/389 | 4.2 (2.4 to 7.3) | <0.001 |
| DERAA + | 12/18 | 123/216 | 1.7 (0.6 to 4.9) | 0.32 |
| Valine + (AA position 11) | 85/107 | 156/281 | 3.1 (1.8 to 5.3) | <0.001 |
| Lysine + (AA position 71) | 89/112 | 262/412 | 2.0 (1.2 to 3.4) | 0.01 |
| Alanine + (AA position 74) | 157/162 | 763/844 | 3.3 (1.3 to 8.7) | 0.01 |
| HLA-B | ||||
| Aspartic acid + (AA position 9) | 35/48 | 140/227 | 1.4 (0.7 to 3.1) | 0.35 |
| HLA-DPB1 | ||||
| Phenylalanine + (AA position 9) | 156/157 | 883/934 | 10.9 (1.5 to 81.2) | 0.02 |
*95% CI for the association between having at least one child (born prior to diagnosis for cases) with one or two alleles (+) of each risk allele group compared with none and RA among mothers. Estimates adjusted for number of live births and carrier status at all other risk allele groups.
AA, amino acid; RA, rheumatoid arthritis.