Contribution of a Non-classical HLA Gene, HLA-DOA, to the Risk of Rheumatoid Arthritis

Citation:

Okada Y, Suzuki A, Ikari K, Terao C, Kochi Y, Ohmura K, Higasa K, Akiyama M, Ashikawa K, Kanai M, Hirata J, Suita N, Teo Y-Y, Xu H, Bae S-C, Takahashi A, Momozawa Y, Matsuda K, Momohara S, Taniguchi A, Yamada R, Mimori T, Kubo M, Brown MA, Raychaudhuri S, Matsuda F, Yamanaka H, Kamatani Y, Yamamoto K. Contribution of a Non-classical HLA Gene, HLA-DOA, to the Risk of Rheumatoid Arthritis [Internet]. Am J Hum Genet 2016;99(2):366-74.

Date Published:

2016 Aug 04

Abstract:

Despite the progress in human leukocyte antigen (HLA) causal variant mapping, independent localization of major histocompatibility complex (MHC) risk from classical HLA genes is challenging. Here, we conducted a large-scale MHC fine-mapping analysis of rheumatoid arthritis (RA) in a Japanese population (6,244 RA cases and 23,731 controls) population by using HLA imputation, followed by a multi-ethnic validation study including east Asian and European populations (n = 7,097 and 23,149, respectively). Our study identified an independent risk of a synonymous mutation at HLA-DOA, a non-classical HLA gene, on anti-citrullinated protein autoantibody (ACPA)-positive RA risk (p = 1.4 × 10(-9)), which demonstrated a cis-expression quantitative trait loci (cis-eQTL) effect on HLA-DOA expression. Trans-ethnic comparison revealed different linkage disequilibrium (LD) patterns in HLA-DOA and HLA-DRB1, explaining the observed HLA-DOA variant risk heterogeneity among ethnicities, which was most evident in the Japanese population. Although previous HLA fine-mapping studies have identified amino acid polymorphisms of the classical HLA genes as driving genetic susceptibility to disease, our study additionally identifies the dosage contribution of a non-classical HLA gene to disease etiology. Our study contributes to the understanding of HLA immunology in human diseases and suggests the value of incorporating additional ancestry in MHC fine-mapping.

Publisher's Version

Last updated on 04/23/2020