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

beta-Globin haplotypes were used to investigate the origin of three common beta-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 beta-thalassemia (beta-thal) and 20 unrelated healthy subjects by polymerase chain reaction (PCR)-based restriction fragment length polymorphism (RFLP) for the beta-globin gene cluster of the following polymorphic restriction sites: HincII 5' to epsilon, HindIII 5' to (G)gamma, HindIII 5' to (A)gamma, HincII in psi beta, HincII 3' to psi beta, AvaII in beta, and HinfI 3' to beta. 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 (beta(A)/beta(A)) 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.