title: Restriction mapping of βS locus among Tunisian sickle-cell patients.
abstract: OBJECTIVE
  The polymorphism of the β-globin gene haplotypes and frameworks is useful in the determination of the unicentric and multicentric origin of a mutational event. In our study, the haplotypes linked to the Tunisian β(S) mutation are determined to improve our knowledge of the chromosomal background of the β-globin gene in sickle-cell anemia in Tunisia.
  
  
  METHODS
  The authors have investigated 242 unrelated individuals. Haplotype analysis was carried out by polymerase chain reaction-restriction fragment length polymorphism-based methods. Seven polymorphic sites in the β-globin gene cluster were examined. The correlation of these various haplotypes with Hb F expression was studied.
  
  
  RESULTS
  The Benin haplotype (Ben) was largely predominant (60.54%) followed by the Atypical haplotype A (8.43%) and Bantu (Ban) (2.71%) haplotypes. A total of 94 chromosomes had atypical haplotypes, 78 (23.49%) had A1 [-----++], 11 (3.31%) had A2 [-------], and five (1.5%) had B1 [--+--++]. The Benin haplotype is associated with a fairly low HbF levels.
  
  
  CONCLUSIONS
  The very high frequency of the Benin haplotype in our study suggests that the β(S) mutation present in Tunisia may have originated from the Benin region and was brought to Tunisia along the slave trade routes. However, another atypical haplotype observed a new emergence in our population and could be considered as specific to Tunisian chromosome β(S).
authors.affiliation: Laboratory of Molecular and Cellular Hematology, Pasteur Institute of Tunis, University of Tunis Elmanar, Tunisia.
authors.forename: Moumni
authors.initials: M
authors.lastname: Imen
authors.forename: Ben Mansour Mosbehi
authors.initials: BM
authors.lastname: Ikbel
authors.forename: Chaouch
authors.initials: C
authors.lastname: Leila
authors.forename: Mellouli
authors.initials: M
authors.lastname: Fethi
authors.forename: Zorai
authors.initials: Z
authors.lastname: Amine
authors.forename: Bejaoui
authors.initials: B
authors.lastname: Mohamed
authors.forename: Abbes
authors.initials: A
authors.lastname: Salem
mesh_terms: D000293:Adolescent; D000755:Anemia, Sickle Cell / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D004252:DNA Mutational Analysis; D004641:Emigration and Immigration; D005260:Female; D005319:Fetal Hemoglobin / Q000235:genetics; D006239:Haplotypes / Q000235:genetics*; D006801:Humans; D007223:Infant; D008297:Male; D005810:Multigene Family; D012150:Polymorphism, Restriction Fragment Length; D015183:Restriction Mapping; D014416:Tunisia; D055544:beta-Globins / Q000235:genetics*
chemical_list: D055544:beta-Globins; D005319:Fetal Hemoglobin