Genome-Wide Association Study of Obstructive Sleep Apnea and Objective Sleep-related Traits Identifies Novel Risk Loci in Han Chinese Individuals.

Previous genetic studies of obstructive sleep apnea (OSA) have limitations in terms of precise case definition, integrated quantitative traits, and interpretation of genetic functions; thus, the heritability of OSA remains poorly explained. To identify novel genetic variants associated with OSA and objective sleep-related traits and to explore their functional roles. A genome-wide association study was performed in 20,590 Han Chinese individuals (5,438 OSA and 15,152 control samples). Human samples and point mutation knockin mice were used for follow-up investigation of gene functions. Two characteristic study-wide significant loci ( < 2.63 × 10) for OSA were identified: the intronic variant rs6455893 on 6q26 (odds ratio [OR] = 1.62; 95% confidence interval [CI], 1.39-1.89;  = 6.98 × 10) and the missense variant rs3746804 (p.Pro267Leu) in the riboflavin transporter on 20p13 (OR = 0.83; 95% CI, 0.79-0.88;  = 7.57 × 10). In addition, 18 genome-wide significant loci associated with quantitative OSA and objective sleep-related traits were identified, 5 of which exceeded the study-wide significance threshold. Rs3746804 was associated with elevated serum riboflavin concentrations, and the corresponding mutation in mice increased riboflavin concentrations, suggesting that this variant may facilitate riboflavin uptake and riboflavin-dependent physiological activity. We identified several novel genome-wide significant loci associated with OSA and objective sleep-related traits. Our findings provide insight into the genetic architecture of OSA and suggest that might be a therapeutic target, whereas riboflavin might be a therapeutic agent.