title: Origin of Hb A2' (Hb B2) [delta16(A13)Gly --> Arg (GGC --> CGC)].
abstract: On a field trip to the Dogon country (le Pays Dogon) in central Mali, we detected a high frequency of the Hb A2 abnormality, reaching higher numbers among blacksmiths (up to 12.4%) living in the same villages. In this report, by direct nucleotide sequencing and employing a polymerase chain reaction-restriction fragment length polymorphism approach, we show that the Hb A2 variant observed in the Dogon population is indeed Hb A2', also called Hb B2, and that in all of the cases the abnormal delta-globin gene is linked to a unique haplotype. The same haplotype was found linked to Hb A2' in the Herero population belonging to the South African Bantu-speaking Blacks from Namibia. Although the unique origin of this mutation in Africa is a possibility, a recurrent mutational event cannot be excluded because the linked beta cluster haplotype is one of the two major haplotypes found in all African populations. A study of populations from other regions of Africa is required to clarify this issue.
authors.affiliation: Laboratory of Molecular Genetics, Department of Life Sciences, Faculty of Science and Technology of Tangier, Tangier, Morocco.
authors.forename: Mohcine
authors.initials: M
authors.lastname: Bennani
authors.forename: Landry-Erik
authors.initials: LE
authors.lastname: Mombo
authors.forename: André
authors.initials: A
authors.lastname: Chaventre
authors.forename: Amina
authors.initials: A
authors.lastname: Barakat
authors.forename: Rolande
authors.initials: R
authors.lastname: Ducrocq
authors.forename: Ronald L
authors.initials: RL
authors.lastname: Nagel
authors.forename: Rajagopal
authors.initials: R
authors.lastname: Krishnamoorthy
mesh_terms: D019943:Amino Acid Substitution; D001120:Arginine; D001483:Base Sequence; D003062:Codon / Q000235:genetics; D006580:Genetic Carrier Screening; D014644:Genetic Variation; D005914:Globins / Q000235:genetics*; D005998:Glycine; D006443:Hemoglobin A2 / Q000235:genetics*; D006801:Humans; D008302:Mali; D005810:Multigene Family; D020125:Mutation, Missense; D016133:Polymerase Chain Reaction / Q000379:methods; D012150:Polymorphism, Restriction Fragment Length
chemical_list: D003062:Codon; D005914:Globins; D006443:Hemoglobin A2; D001120:Arginine; D005998:Glycine