In a case-control association study with 3716 North Americans of Hispanic descent and 4867 North Americans of European descent, we show that the associations of rs17849502 (NCF2 His-389 → Gln) and rs13306575 (NCF2 Arg-395 → Trp) with systemic lupus erythematosus are independent.
The association between NCF2 and SLE can be attributed to a single nonsynonymous coding mutation in exon 12, the effect of which is the substitution of histidine-389 with glutamine (H389Q) in the PB1 domain of the NCF2 protein, with glutamine being the risk allele.