Linkage‐disequilibrium of the senegal haplotype with the β^s gene in the republic of guinea

Abstract

We have determined the beta gene cluster haplotype in 40 chromosomes carrying the beta S mutation from individuals of the major ethnic groups living in the Republic of Guinea. Thirty-one of these were either the typical (n = 29) or the atypical (n = 2) Senegal haplotype demonstrating that in this region of Atlantic West Africa, the sickle mutation is in linkage disequilibrium with this particular beta-gene cluster haplotype. Two individuals carrying one chromosome bearing the Benin haplotype were of Malinke ethnic origin. This is in keeping with the hypothesis that the Senegal beta-gene cluster haplotype is linked to the beta S gene in Atlantic West Africa.

Molecular Analysis of the β-Globin Gene Cluster in the Niokholo Mandenka Population Reveals a Recent Origin of the βS Senegal Mutation

“…In keeping with this interpretation and with our own results, a recent survey of the haplotypic diversity at the G6PD locus (Tishkoff et al 2001) also suggests that two protective mutations against malaria had appeared at that locus within the last 10,000 years. The present results are also in agreement with studies reported elsewhere (Lapoumeroulie et al 1992;Sow et al 1995) that show b S haplotypes to be generally homogeneous in well-defined ethnic groups. Different results are found in other molecular-diversity studies that have focused on heterogeneous samples of b S homozygous patients, which showed a diversity of b S chromosomes (Pagnier et al 1984).…”

“…The sequencing of individual chromosomes in the polymorphic repeated region upstream of the b-globin gene confirms a strict association between the b S mutation and the Senegal haplotype. The Senegal DNA sequence has already been shown to predominate among b S chromosomes in nearby Guinea without becoming monomorphic (31 of 40 sampled chromosomes; Sow et al 1995), but in that case the analyzed sample was both geographically and ethnically much more heterogeneous than the present sample from the Niokholo Manden-kalu. The b S mutation previously had been found to be associated with several RFLP haplotypes in an urban sample from Dakar, with the predominance of the Senegal RFLP haplotype but also with significant frequencies of the Benin and Bantu haplotypes (Pagnier et al 1984).…”

Beta-globin gene cluster haplotypes in Venezuelan sickle cell patients from the State of Aragua

“…Fifty-two percent of the SCD patients studied presented heterozygous haplotypes, as was expected due to the 22 Moreno et al admixture process which occurs in our population; in a study carried out on African SCD patients, the vast majority of haplotypes were found in homozygosity (Sow et al, 1995). Our results differed significantly from those reported by Arends et al (2000) in another study performed on sickle cell Venezuelan patients from all over the country (χ 2 = 14.62; d.f.…”