Nucleotide sequence evidence of the unicentric origin of the βCmutation in Africa

✍ Scribed by Guy Trabuchet; Jacques Elion; Olga Dunda; Claudine Lapouméroulie; Rolande Ducrocq; Sellama Nadifi; Isidore Zohoun; Andre Chaventre; Pierre Carnevale; Ronald L. Nagel; Rajagopal Krishnamoorthy; Dominique Labie

• Publisher: Springer
• Year: 1991
• Tongue: English
• Weight: 556 KB
• Volume: 87
• Category: Article
• ISSN: 0340-6717
• DOI: 10.1007/bf00209020

✦ Synopsis

The origin of the beta C mutation was studied by characterizing nucleotide sequence polymorphisms on beta C chromosomes of patients from various African countries. In the majority of cases, the beta C mutation was found in linkage disequilibrium with a single chromosomal structure as defined by classical RFLP haplotypes, intergenic nucleotide sequence polymorphisms immediately upstream of the beta-globin gene, and intragenic beta-globin gene polymorphisms (frameworks). In addition, three atypical variant chromosomes carrying the beta C mutation were observed, and are most probably explained either by a meiotic recombination (two cases) or by one nucleotide substitution occurring in an unstable array of tandemly repeated sequences (one case). These data demonstrate the unicentric origin of the beta C mutation in central West Africa, with subsequent mutational modification in a small number of instances. The data also supports gene flow of the beta C chromosome from subsaharan Africa to North Africa.