Genome-wide association study identifies novel risk variants from RPS6KA1, CADPS, VARS, and DHX58 for fasting plasma glucose in Arab population

Sci Rep. 2020 Jan 13;10(1):152. doi: 10.1038/s41598-019-57072-9.

Abstract

Consanguineous populations of the Arabian Peninsula, which has seen an uncontrolled rise in type 2 diabetes incidence, are underrepresented in global studies on diabetes genetics. We performed a genome-wide association study on the quantitative trait of fasting plasma glucose (FPG) in unrelated Arab individuals from Kuwait (discovery-cohort:n = 1,353; replication-cohort:n = 1,196). Genome-wide genotyping in discovery phase was performed for 632,375 markers from Illumina HumanOmniExpress Beadchip; and top-associating markers were replicated using candidate genotyping. Genetic models based on additive and recessive transmission modes were used in statistical tests for associations in discovery phase, replication phase, and meta-analysis that combines data from both the phases. A genome-wide significant association with high FPG was found at rs1002487 (RPS6KA1) (p-discovery = 1.64E-08, p-replication = 3.71E-04, p-combined = 5.72E-11; β-discovery = 8.315; β-replication = 3.442; β-combined = 6.551). Further, three suggestive associations (p-values < 8.2E-06) with high FPG were observed at rs487321 (CADPS), rs707927 (VARS and 2Kb upstream of VWA7), and rs12600570 (DHX58); the first two markers reached genome-wide significance in the combined analysis (p-combined = 1.83E-12 and 3.07E-09, respectively). Significant interactions of diabetes traits (serum triglycerides, FPG, and glycated hemoglobin) with homeostatic model assessment of insulin resistance were identified for genotypes heterozygous or homozygous for the risk allele. Literature reports support the involvement of these gene loci in type 2 diabetes etiology.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabs / genetics*
  • Biomarkers / analysis*
  • Blood Glucose / analysis*
  • Calcium-Binding Proteins / genetics
  • Case-Control Studies
  • Diabetes Mellitus, Type 2 / blood
  • Diabetes Mellitus, Type 2 / epidemiology
  • Diabetes Mellitus, Type 2 / genetics*
  • Diabetes Mellitus, Type 2 / pathology
  • Fasting
  • Female
  • Gene Expression Profiling
  • Gene Expression Regulation*
  • Genetic Predisposition to Disease*
  • Genome-Wide Association Study
  • Genotype
  • Humans
  • Insulin Resistance
  • Kuwait / epidemiology
  • Male
  • Phenotype
  • Polymorphism, Single Nucleotide*
  • Prognosis
  • RNA Helicases / genetics
  • Ribosomal Protein S6 Kinases, 90-kDa / genetics
  • Valine-tRNA Ligase / genetics
  • Vesicular Transport Proteins / genetics

Substances

  • Biomarkers
  • Blood Glucose
  • CADPS2 protein, human
  • Calcium-Binding Proteins
  • Vesicular Transport Proteins
  • Ribosomal Protein S6 Kinases, 90-kDa
  • ribosomal protein S6 kinase, 90kDa, polypeptide 3
  • DHX58 protein, human
  • RNA Helicases
  • Valine-tRNA Ligase