Empirical assessment of allele frequencies of genome wide association study variants associated with obstructive sleep apnea.

Objective: Obstructive Sleep Apnea (OSA) is a heterogeneous disorder with a complex interplay of genetic and environmental factors. Over the years, with advancement in genotyping and sequencing techniques, various loci have shown an association with OSA. It is pertinent to understand the status of these associated variants in different ethnic groups. The aim of the study was to assess the genetic affinity among different population groups by evaluating the risk allele frequencies of variants associated with OSA.

Method: The variants associated with OSA were obtained from the GWAS catalog with a significant value of <5 × 10; 95 variants were obtained (www.ebi.ac.uk/gwas). Further, the variants were narrowed down on the basis of risk allele frequencies (>5%). The was calculated to assess the genetic affinity between super population groups and among the sub-population groups present in the 1000 genome project.

Result: The values observed indicated all super populations were genetically related (SAS, AMR, EAS and EUR) except in the African (AFR) population group. Further, the closely related super population , SAS, AMR, EAS and EUR when bifurcated on the basis of sub-population groups shows population stratification and SAS population groups form separate clusters on the MDS plot.

Conclusion: The study highlights genetic heterogeneity among different population groups that gets diluted and results are biased when the samples are pooled irrespective of their endogamous groups. Our results provide insight to researchers to target specific endogamous groups for future studies on OSA.