Haplotype Map of Sickle Cell Anemia in Tunisia

Abstract

β-Globin haplotypes are important to establish the ethnic origin and predict the clinical development of sickle cell disease patients (SCD). To determine the chromosomal background ofβSTunisian sickle cell patients, in this first study in Tunisia, we have explored four polymorphic regions ofβ-globin cluster on chromosome 11. It is the 5′ region ofβ-LCR-HS2site, the intervening sequence II (IVSII) region of two fetal (γGandγA) genes and the 5′ region ofβ-globingene. The results reveal a high molecular diversity of a microsatellite configuration describing the sequences haplotypes. The linkage disequilibrium analysis showed various haplotype combinations giving 22 “extended haplotypes”. These results confirm the utility of theβ-globin haplotypes for population studies and contribute to knowledge of the Tunisian gene pool, as well as establishing the role of genetic markers in physiopathology of SCD.