Association of an ERAP1 ERAP2 haplotype with familial ankylosing spondylitis.

Abstract

To assess whether there is excess transmission of alleles from the ERAP1 ERAP2 locus in families with ankylosing spondylitis (AS). 199 multiplex families with AS with four non-synonymous single nucleotide polymorphisms (SNPs), three in the endoplasmic reticulum aminopeptidase 1 (ERAP1) gene (rs27044, rs10050860 and rs30187) and one in the endoplasmic reticulum aminopeptidase 2 (ERAP2) gene (rs2549782), were genotyped and family-based association analyses were performed. Family-based association testing (FBAT -e; empirical variance option) analysis showed that ERAP1 rs30187[T] was associated with AS (additive model: p=0.02; dominant model: p=0.007). Haplotype permutation tests (HBAT-p) showed that a haplotype in the ERAP1 and ERAP2 locus (rs27044[G] rs30187[T] rs2549782[T]) was significantly associated with AS (two-sided p value by permutation test 0.009 for additive and 0.008 for dominant model, respectively). This study shows that one ERAP1 SNP and a haplotype in the ERAP1 and ERAP2 locus are associated with familial AS.