Haplotype Analysis of Three Common β-Thalassemia Mutations in Syrian Patients

Abstract

β-Globin haplotypes were used to investigate the origin of three common β-globin mutations, IVS-I-110 (G>A); HBB: c.93-21G>A, IVS-I-1 (G>A); HBB: c.92 + 1G>A and codon 39 (C>T); HBB: c.118C > T in Syrian patients. Haplotype analysis was done for 49 unrelated patients with β-thalassemia (β-thal) and 20 unrelated healthy subjects by polymerase chain reaction (PCR)-based restriction fragment length polymorphism (RFLP) for the β-globin gene cluster of the following polymorphic restriction sites: HincII 5' to ε, HindIII 5' to Gγ, HindIII 5' to Aγ, HincII in ψβ, HincII 3' to ψβ, AvaII in β, and HinfI 3' to β. The IVS-I-110 mutation was associated with three haplotypes: I [+ – – – – + +] (79.4%), V [+ – – – – + –] (5.9%) and VII [+ – – – – – +] (14.7%), while, the two mutations IVS-I-1 and codon 39 were be linked to a single haplotype V (100.0%) and II [– + + – + + +] (100.0%), respectively. The normal chromosomes (βA/βA) were associated with four haplotypes, I (50.0%), II (7.5%), V (32.5%) and VII (10.0%). In the Syrian population, the IVS-I-110 mutation was associated with multi haplotypes, whereas the IVS-I-1 and codon 39 mutations have a single origin. More studies for the other mutations will be very useful for genetic epidemiological studies in Syria.