• Genetic correlations and genome-wide associations of cortical structure in general population samples of 22,824 adults

      Hofer, Edith; Roshchupkin, Gennady V.; Adams, Hieab H.H.; Knol, Maria J.; Lin, Honghuang; Li, Shuo; Zare, Habil; Ahmad, Shahzad; Armstrong, Nicola J.; Satizabal, Claudia L.; et al. (Springer Nature, 2020-12-01)
      Cortical thickness, surface area and volumes vary with age and cognitive function, and in neurological and psychiatric diseases. Here we report heritability, genetic correlations and genome-wide associations of these cortical measures across the whole cortex, and in 34 anatomically predefined regions. Our discovery sample comprises 22,824 individuals from 20 cohorts within the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) consortium and the UK Biobank. We identify genetic heterogeneity between cortical measures and brain regions, and 160 genome-wide significant associations pointing to wnt/β-catenin, TGF-β and sonic hedgehog pathways. There is enrichment for genes involved in anthropometric traits, hindbrain development, vascular and neurodegenerative disease and psychiatric conditions. These data are a rich resource for studies of the biological mechanisms behind cortical development and aging.
    • A multi-ethnic epigenome-wide association study of leukocyte DNA methylation and blood lipids

      Jhun, Mina-A; Mendelson, Michael; Wilson, Rory; Gondalia, Rahul; Joehanes, Roby; Salfati, Elias; Zhao, Xiaoping; Braun, Kim Valeska Emilie; Do, Anh Nguyet; Hedman, Åsa K; et al. (Springer Nature, 2021-06-28)
      Here we examine the association between DNA methylation in circulating leukocytes and blood lipids in a multi-ethnic sample of 16,265 subjects. We identify 148, 35, and 4 novel associations among Europeans, African Americans, and Hispanics, respectively, and an additional 186 novel associations through a trans-ethnic meta-analysis. We observe a high concordance in the direction of effects across racial/ethnic groups, a high correlation of effect sizes between high-density lipoprotein and triglycerides, a modest overlap of associations with epigenome-wide association studies of other cardio-metabolic traits, and a largely non-overlap with lipid loci identified to date through genome-wide association studies. Thirty CpGs reached significance in at least 2 racial/ethnic groups including 7 that showed association with the expression of an annotated gene. CpGs annotated to CPT1A showed evidence of being influenced by triglycerides levels. DNA methylation levels of circulating leukocytes show robust and consistent association with blood lipid levels across multiple racial/ethnic groups.