Table 2.

ERAP1 haplotype combination frequencies

Haplotype combination	RA controls, n (%)	AS cases, n (%)	P value†
	46	213
II + IV (*002 + *011) MKDRQ + MRDRE	12 (26)	67 (31.5)	0.6
IV + IV MRDRE + MRDRE	9 (19.6)	28 (13.2)	0.3
I + II (*001 + *002) VRNQE + MKDRQ	7 (15.2)	31 (14.6)	1
I + IV (*001 + *008) VRNQE + MRDRE	5 (10.9)	28 (13.2)	0.8
I + I (*001 + *001) VRNQE + VRNQE	4 (8.7)	6 (2.8)	0.08
IV + V MR DRE + MKDRE	3 (6.5)	9 (4.2)	0.5
II + II (*002 + *002) MKDRQ + MKDRQ	2 (4.4)	18 (8.5)	0.5
II + V MKDRQ + MKDRE	2 (4.4)	12 (5.6)	1
I + VV RNQE + MKDRE	2 (4.4)	3 (1.4)	0.2
V + VI MKDRE + VRNRQ	0	6 (2.8)	0.6
IV + VII MRDRE + MRNRE	0	3 (1.4)	1
V + V MKDRE + MKDRE	0	1 (0.5)	1
IV + VI MRDRE + VRNRQ	0	1 (0.5)	1

Roman numerals denote haplotypes defined in the current study. Corresponding putative alleles described by Reeves et al. (12) are shown in parentheses in the first column. Amino acids are shown in the order: M349V (rs2287987), K528R (rs30187), D575N (rs10050860), R725Q (rs17482078), and Q730E (rs27044).

^†Fisher’s exact test performed on family AS cases versus RA controls.