Epigenome-wide association study for perceived discrimination among sub-Saharan African migrants in Europe - the RODAM study

Loes C Van Der Laan,Kerstin Klipstein-Grobusch,Felix P Chilunga,Karlijn A C Meeks,Adebowale Adeyemo,Charles Agyemang,Mohammad H Zafarmand,Marcel M A M Mannens,Andrea Venema,Peter Henneman,Liam Smeeth

doi:10.1038/s41598-020-61649-0

Abstract

Sub-Saharan African (SSA) migrants in Europe experience psychosocial stressors, such as perceived discrimination (PD). The effect of such a stressor on health could potentially be mediated via epigenetics. In this study we performed an epigenome-wide association study (EWAS) to assess the association between levels of PD with genome-wide DNA methylation profiles in SSA migrants. The Illumina 450 K DNA-methylation array was used on whole blood samples of 340 Ghanaian adults residing in three European cities from the cross-sectional Research on Obesity and Diabetes among African Migrants (RODAM) study. PD was assessed using sum scores of the Everyday Discrimination Scale (EDS). Differentially methylated positions and regions (DMPs and DMRs) were identified through linear regression analysis. Two hypo-methylated DMPs, namely cg13986138 (CYFIP1) and cg10316525(ANKRD63), were found to be associated with PD. DMR analysis identified 47 regions associated with the PD. To the best of our knowledge, this survey is the first EWAS for PD in first generation SSA migrants. We identified two DMPs associated with PD. Whether these associations underlie a consequence or causal effect within the scope of biological functionality needs additional research.

Highlights

International migration from low- and middle income to high income countries has been increasing over the years and migrants face a plethora of psychosocial stressors in the host countries, including perceived discrimination (PD)[1]
We evaluated 3 indicators for socio-economic status (SES) and found source of income correlated with the summed Everyday Discrimination Scale (EDS), but not attained education level nor occupation
This study describes the first epigenome-wide association study (EWAS) for perceived discrimination in first generation Sub-Saharan African (SSA) migrants in Europe

Summary

Introduction

International migration from low- and middle income to high income countries has been increasing over the years and migrants face a plethora of psychosocial stressors in the host countries, including perceived discrimination (PD)[1]. Psychosocial stress has been linked to changes in DNA methylation of genes implicated in the stress response system[15] These genes include the glucocorticoid receptor gene (NR3C1), serotonin transporter gene (SLC6A4) and the corticotrophin-releasing factor (CRF) gene[15,16,17]. Since epigenetics is known to be affected by environmental factors, we hypothesized that exposure to discrimination might result in an altered state of DNA methylation, globally or at specific loci[13]. Previous reported studies showed that PD represents an important factor associated with the stress response system and mental health disorders and represents relevant psychosocial stressor[18]. No study has assessed the association between discrimination and epigenetics in SSA migrants. We conducted an epigenome-wide association study (EWAS) where we aimed to detect novel epigenetic loci associated with PD as assessed by the Everyday Discrimination Scale (EDS) in a cohort of Ghanaian migrants from the RODAM study

Objectives

Methods

Results

Conclusion