title: Haplotype analyses of haemoglobin C and haemoglobin S and the dynamics of the evolutionary response to malaria in Kassena-Nankana District of Ghana.
abstract: BACKGROUND
  Haemoglobin S (HbS) and C (HbC) are variants of the HBB gene which both protect against malaria. It is not clear, however, how these two alleles have evolved in the West African countries where they co-exist at high frequencies. Here we use haplotypic signatures of selection to investigate the evolutionary history of the malaria-protective alleles HbS and HbC in the Kassena-Nankana District (KND) of Ghana.
  
  
  RESULTS
  The haplotypic structure of HbS and HbC alleles was investigated, by genotyping 56 SNPs around the HBB locus. We found that, in the KND population, both alleles reside on extended haplotypes (approximately 1.5 Mb for HbS and 650 Kb for HbC) that are significantly less diverse than those of the ancestral HbA allele. The extended haplotypes span a recombination hotspot that is known to exist in this region of the genome
  
  
  CONCLUSIONS
  Our findings show strong support for recent positive selection of both the HbS and HbC alleles and provide insights into how these two alleles have both evolved in the population of northern Ghana.
authors.affiliation: Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana. AGhansah@noguchi.mimcom.org
authors.forename: Anita
authors.initials: A
authors.lastname: Ghansah
authors.forename: Kirk A
authors.initials: KA
authors.lastname: Rockett
authors.forename: Taane G
authors.initials: TG
authors.lastname: Clark
authors.forename: Michael D
authors.initials: MD
authors.lastname: Wilson
authors.forename: Kwadwo A
authors.initials: KA
authors.lastname: Koram
authors.forename: Abraham R
authors.initials: AR
authors.lastname: Oduro
authors.forename: Lucas
authors.initials: L
authors.lastname: Amenga-Etego
authors.forename: Thomas
authors.initials: T
authors.lastname: Anyorigiya
authors.forename: Abraham
authors.initials: A
authors.lastname: Hodgson
authors.forename: Paul
authors.initials: P
authors.lastname: Milligan
authors.forename: William O
authors.initials: WO
authors.lastname: Rogers
authors.forename: Dominic P
authors.initials: DP
authors.lastname: Kwiatkowski
mesh_terms: D000483:Alleles; D016022:Case-Control Studies; D005006:Ethnicity; D019143:Evolution, Molecular; D005787:Gene Frequency; D056426:Genetic Loci; D060005:Genotyping Techniques / Q000379:methods; D005869:Ghana; D006239:Haplotypes; D006441:Hemoglobin A / Q000235:genetics; D006444:Hemoglobin C / Q000235:genetics*; D006451:Hemoglobin, Sickle / Q000235:genetics*; D006801:Humans; D008288:Malaria / Q000097:blood / Q000208:ethnology / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D011995:Recombination, Genetic; D055544:beta-Globins / Q000235:genetics
chemical_list: D006451:Hemoglobin, Sickle; D055544:beta-Globins; D006444:Hemoglobin C; D006441:Hemoglobin A