Hemoglobinopathies in mountainous region of Thua Thien Hue, Vietnam

The spectrum of ß-thalassemia mutations was determined in two Districts of the Central province of Thua Thien Hue (A Luoi and Nam Dong).A community-based assessment was conducted to estimate the prevalence of hemoglobinopathies and to assess their molecular basis. 1100 participants were enrolled including 83.73% of the minorities and 16.27% of the Kinh.The blood samples were firstly screened by complete blood count and osmotic fragility test. Hemoglobinopathies were diagnosed by electrophoresis and High Performance Liquid Chromatography. Mutations at the level of β and α globin genes were identified by DNA sequencing.Four mutations of the β0-thalassemia were observed in five subjects:- Two of these showed theAAG→TAG at codon 17. One was in combination with the βEgene (genotype β0/βE) and one was β0/β.- One showed the G→T at the IVS-I nt 1 (genotype β0/βE). Due to the presence of Hb F, the γ globin genes were also sequenced. The C→T in the promoter region, at position -158 of theGγ gene (also known as theXmnI polymorphism) was found.- One was the carrier of a 4 bp deletion (-TTCT) involving codons 41/42 (genotype β0/β).- One was the carrier of the G insertion at codons 14/15 (genotype β0/β).Sequencing also confirmed that the G→A at codon 26 (GAG→AAG) of the β globin gene is responsible for Hb E.The prevalence of the hemoglobinopathies appears to be higher within the minorities than the Kinh population.