Publication Date
2015
Journal Title
Mol Med
Abstract
To investigate the genetics of late-onset myasthenia gravis (LOMG), we conducted a genome-wide association study imputation of >6 million SNPs in 532 LOMG cases (anti-acetylcholine receptor (AChR) antibody positive, onset age >/=50 years) and 2,128 controls matched for sex and population substructure. The data confirm reported TNFRSF11A associations [rs4574025, P = 3.9x10-07, odds ratio (OR) = 1.42] and identify a novel candidate gene, ZBTB10, achieving genome-wide significance (rs6998967, P = 8.9x10-10, OR = 0.53). Several other SNPs showed suggestive significance including rs2476601 (P = 6.5x10-06, OR =1.62) encoding the PTPN22 R620W variant noted in early-onset MG (EOMG) and other autoimmune diseases. In contrast, EOMG-associated SNPs in TNIP1 showed no association in LOMG, nor did other loci suggested for EOMG. Many SNPs within the major histocompatibility complex (MHC) region showed strong associations in LOMG, but with smaller effect sizes than in EOMG (highest OR ~2 vs. ~6 in EOMG). Moreover, the strongest associations were in opposite directions from EOMG, including an OR of 0.54 for DQA1*05:01 in LOMG (P = 5.9x10-12) vs. 2.82 in EOMG (P = 3.86x10-45). Association and conditioning studies for the MHC region showed three distinct and largely independent association peaks for LOMG corresponding to i) MHC class II (highest attenuation when conditioning on DQA1), ii) HLA-A and iii) MHC class III SNPs. Conditioning studies of HLA amino acid residues also suggest potential functional correlates. Together, these findings emphasize the value of subgrouping MG patients for clinical and basic investigations, and imply distinct predisposing mechanisms in LOMG.
Volume Number
21
Issue Number
1
Pages
769-781
Document Type
Article
EPub Date
2015/11/13
Status
Faculty
Facility
School of Medicine
Primary Department
Molecular Medicine
Additional Departments
General Internal Medicine
PMID
DOI
10.2119/molmed.2015.00232