title: Associations between Common Variants in Iron-Related Genes with Haematological Traits in Populations of African Ancestry.
abstract: BACKGROUND
  Large genome-wide association (GWA) studies of European ancestry individuals have identified multiple genetic variants influencing iron status. Studies on the generalizability of these associations to African ancestry populations have been limited. These studies are important given interethnic differences in iron status and the disproportionate burden of iron deficiency among African ancestry populations.
  
  
  METHODS
  We tested the associations of 20 previously identified iron status-associated single nucleotide polymorphisms (SNPs) in 628 Kenyans, 609 Tanzanians, 608 South Africans and 228 African Americans. In each study, we examined the associations present between 20 SNPs with ferritin and haemoglobin, adjusting for age, sex and CRP levels.
  
  
  RESULTS
  In the meta analysis including all 4 African ancestry cohorts, we replicated previously reported associations with lowered haemoglobin concentrations for rs2413450 (β = -0.19, P = 0.02) and rs4820268 (β = -0.16, P = 0.04) in TMPRSS6. An association with increased ferritin concentrations was also confirmed for rs1867504 in TF (β = 1.04, P = <0.0001) in the meta analysis including the African cohorts only.
  
  
  CONCLUSIONS
  In all meta analyses, we only replicated 4 of the 20 single nucleotide polymorphisms reported to be associated with iron status in large GWA studies of European ancestry individuals. While there is now evidence for the associations of a number of genetic variants with iron status in both European and African ancestry populations, the considerable lack of concordance highlights the importance of continued ancestry-specific studies to elucidate the genetic underpinnings of iron status in ethnically diverse populations.
authors.affiliation: Division of Human Nutrition, Wageningen University, Wageningen, the Netherlands.|International institute of Tropical Agriculture (IITA), Dar es Salaam, Tanzania.
authors.forename: Wanjiku N
authors.identifier: http://orcid.org/0000-0002-3605-0304
authors.initials: WN
authors.lastname: Gichohi-Wainaina
authors.affiliation: Translational Gerontology Branch, National Institute on Aging, Baltimore, MD, United States of America.
authors.forename: Toshiko
authors.initials: T
authors.lastname: Tanaka
authors.affiliation: Centre of Excellence for Nutrition, North-West University (Potchefstroom campus), Potchefstroom, South Africa.
authors.forename: G Wayne
authors.initials: GW
authors.lastname: Towers
authors.affiliation: Cell Biology and Immunology Group, Wageningen University, Wageningen, The Netherlands.|Medical Research Council (MRC) International Nutrition Group, London School of Hygiene and Tropical Medicine, London, United Kingdom.|Medical Research Council Banjul, The Gambia.
authors.forename: Hans
authors.initials: H
authors.lastname: Verhoef
authors.affiliation: Laboratory for Microbiology and Infection Control, Amphia Hospital, Breda, The Netherlands.|Department of Medical Microbiology and Immunology, Admiraal De Ruyter Hospital, Goes The Netherlands.
authors.forename: Jacobien
authors.initials: J
authors.lastname: Veenemans
authors.affiliation: Division of Human Nutrition, Wageningen University, Wageningen, the Netherlands.|HarvestPlus, International Center for Tropical Agriculture (CIAT), Cali, Colombia.
authors.forename: Elise F
authors.initials: EF
authors.lastname: Talsma
authors.affiliation: Division of Human Nutrition, Wageningen University, Wageningen, the Netherlands.
authors.forename: Jan
authors.initials: J
authors.lastname: Harryvan
authors.affiliation: Nutrition, Metabolism and Genomics group, Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands.
authors.forename: Mark V
authors.initials: MV
authors.lastname: Boekschoten
authors.affiliation: Division of Human Nutrition, Wageningen University, Wageningen, the Netherlands.
authors.forename: Edith J
authors.initials: EJ
authors.lastname: Feskens
authors.affiliation: Division of Human Nutrition, Wageningen University, Wageningen, the Netherlands.
authors.forename: Alida
authors.initials: A
authors.lastname: Melse-Boonstra
mesh_terms: D000328:Adult; D044383:Black People / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D005293:Ferritins / Q000235:genetics*; D005787:Gene Frequency / Q000235:genetics; D055106:Genome-Wide Association Study; D006454:Hemoglobins / Q000235:genetics*; D006801:Humans; D007501:Iron / Q000378:metabolism*; D008297:Male; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D001741:Black or African American
chemical_list: D006454:Hemoglobins; D005293:Ferritins; D007501:Iron