A recent GWAS analysis in the Middle Eastern Qatari population has identified genetic associations in 45 clinically relevant traits.
Over the past decade, genome-wide association studies (GWAS) have provided new insights into the genetic determinants of many clinically relevant traits. However, most of the studies to date have been in European or East Asian populations. Middle Eastern populations have been under-represented. This complicates the derivation of polygenic scores as many trait-associated variants show differences in allele frequencies and effects sizes across populations. Studies have shown that applying polygenic risk scores from studies in European populations have lower predictive performance in non-European populations. This has emphasised the need to conduct GWAS in non-European populations that are less represented in previously published studies.
Qatar is among one of the first countries to launch its own large-scale, national genome project. The Qatar Genome Program combines whole-genome sequencing data with comprehensive phenotypic data collected in the Qatar Biobank. The aim of the project is to gain insight into the population structure and genetic architecture of clinically relevant phenotypes in the Middle Eastern Qatari population.
In the present study, published in Nature Communications, researchers used whole-genome sequence data from 6,218 participants of the Qatar Biobank and further replication in another 7,768 subjects. They performed a comprehensive heritability and genome-wide association study for 45 relevant traits in the Middle Eastern population of Qatar.
This study identified 281 independent signals that replicate known associations. The allele frequencies for replicated loci showed higher correlations with European populations than with African or Japanese. They also found 17 novel and unique signals providing insights into the biological pathways regulating these traits.
The team also assessed the translatability of polygenic scores derived from other populations to the Qatari population. As they found higher correlations with European populations, the team focused their analysis on polygenic scores derived from European populations. From this, they observed that European-derived polygenic scores have reduced predictive performance in the Qatari population. This could have implications for the translation of polygenic score between populations.
Omar Albagha, Principal Investigator from HBKU’s College of Health and Life Sciences, expressed:
“The study provides new insights into the genetic architecture of clinical laboratory tests and identifies for the first time genetic variations that are specific to the population of Qatar. The study also shows that findings from genetic studies in European populations don’t translate well when applied to our population in the Middle East. This argues for further studies to define the genetic architecture of diseases in our region. We are excited because the study represents a foundation for the implementation of precision medicine in the Middle East.”
Image by LionFive from Pixabay