Widespread non-additive and interaction effects within HLA loci modulate the risk of autoimmune diseases

Citation:

Lenz TL#, Deutsch AJ#, Han B, Hu X, Okada Y, Eyre S, Knapp M, Zhernakova A, Huizinga TWJ, Abecasis G, Becker J, Boeckxstaens GE, Chen W-M, Franke A, Gladman DD, Gockel I, Gutierrez-Achury J, Martin J, Nair RP, Nöthen MM, Onengut-Gumuscu S, Rahman P, Rantapää-Dahlqvist S, Stuart PE, Tsoi LC, van Heel DA, Worthington J, Wouters MM, Klareskog L, Elder JT, Gregersen PK, Schumacher J, Rich SS, Wijmenga C, Sunyaev SR, de Bakker PIW*, Raychaudhuri S*. Widespread non-additive and interaction effects within HLA loci modulate the risk of autoimmune diseases [Internet]. Nat Genet 2015;47(9):1085-90.

Date Published:

2015 Sep

Abstract:

Human leukocyte antigen (HLA) genes confer substantial risk for autoimmune diseases on a log-additive scale. Here we speculated that differences in autoantigen-binding repertoires between a heterozygote's two expressed HLA variants might result in additional non-additive risk effects. We tested the non-additive disease contributions of classical HLA alleles in patients and matched controls for five common autoimmune diseases: rheumatoid arthritis (ncases = 5,337), type 1 diabetes (T1D; ncases = 5,567), psoriasis vulgaris (ncases = 3,089), idiopathic achalasia (ncases = 727) and celiac disease (ncases = 11,115). In four of the five diseases, we observed highly significant, non-additive dominance effects (rheumatoid arthritis, P = 2.5 × 10(-12); T1D, P = 2.4 × 10(-10); psoriasis, P = 5.9 × 10(-6); celiac disease, P = 1.2 × 10(-87)). In three of these diseases, the non-additive dominance effects were explained by interactions between specific classical HLA alleles (rheumatoid arthritis, P = 1.8 × 10(-3); T1D, P = 8.6 × 10(-27); celiac disease, P = 6.0 × 10(-100)). These interactions generally increased disease risk and explained moderate but significant fractions of phenotypic variance (rheumatoid arthritis, 1.4%; T1D, 4.0%; celiac disease, 4.1%) beyond a simple additive model.

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Last updated on 04/23/2020