Objective: Antinuclear antibodies (ANA) are detected in up to 14% of the population, and many individuals with ANA are asymptomatic. The literature on the genetic contribution to asymptomatic ANA positivity is limited. In this study, we aimed to perform a genome-wide association study of asymptomatic ANA positivity in multiple populations.
Methods: Asymptomatic individuals who were either ANA positive or ANA negative from the All of Us Research Program were included in this study, selecting those with an ANA test performed by immunofluorescence and no evidence of autoimmune disease. Imputation was performed, and a multipopulation meta-analysis including approximately 6 million single-nucleotide polymorphisms (SNPs) was conducted. Genome-wide SNP-based heritability was estimated using the Genome-wide Complex Trait Analysis software. A cumulative genetic risk score for lupus was constructed using previously reported genome-wide significant loci.
Results: A total of 1,955 asymptomatic ANA positive and 3,634 asymptomatic ANA negative individuals across three populations were included. The multipopulation meta-analysis revealed SNPs with a suggestive association (P <1 × 10-5) across 8 different loci, but no genome-wide significant loci were identified. A gene variant upstream of HLA-DQB1, (rs17211748, P = 1.4 × 10-6, odds ratio 0.82, 95% confidence interval 0.76-0.89), showed the most significant association. The heritability of asymptomatic ANA positivity was estimated to be 24.9%. Individuals who were asymptomatic and ANA positive did not exhibit increased cumulative genetic risk for lupus compared with individuals who were ANA negative.
Conclusion: ANA production is not associated with significant genetic risk and is primarily determined by environmental factors.
© 2024 The Author(s). Arthritis & Rheumatology published by Wiley Periodicals LLC on behalf of American College of Rheumatology.