title: Genotype and phenotype characterizations in a large cohort of β-thalassemia heterozygote with different forms of α-thalassemia in northeast Thailand.
abstract: In order to update the molecular basis of β-thalassemia and describe hematological features among different mutations and the concurrent of α- and β-thalassemias, 849 unrelated β-thalassemia heterozygotes recruited in northeast Thailand during a prevention and control program were studied. β- and α-thalassemia mutations were investigated using the polymerase chain reaction (PCR)-based technologies and hematological parameters were recorded using standard methods. Seventeen different mutations including both β(0)- and β(+) -thalassemias were identified. Eight of these 17 β-thalassemia alleles accounted for 97.4%, others were found at lower frequencies (<1.0%). Of the 849 cases, 626 were investigated for common α-thalassemia mutations and 155 (24.8%) were found to be co-inherited with different forms of α-thalassemia. Comparison of the hematological parameters among different β-thalassemia mutations revealed an increasing trend of MCV and MCH in a group of heterozygous states for the 3.4kb deletion and the A-G substitution at nucleotide (NT) -28. Hb A(2) and Hb F levels in individuals with the 3.4kb deletion were significantly higher than those with other mutations. Interaction of each β-thalassemia mutation with α-thalassemia did not affect the diagnostic ranges of Hb A(2) and Hb F, though the significantly increased MCV and MCH was noted. These findings underline the heterogeneity of β-thalassemia and the importance of hematological and molecular analyses of both α-and β-thalassemias in the diagnosis and genetic counseling of the couples at-risk of having babies with severe thalassemia diseases in the region.
authors.affiliation: Biomedical Science Program, Graduate School, Khon Kaen University, Thailand.
authors.forename: Supawadee
authors.initials: S
authors.lastname: Yamsri
authors.forename: Kanokwan
authors.initials: K
authors.lastname: Sanchaisuriya
authors.forename: Goonnapa
authors.initials: G
authors.lastname: Fucharoen
authors.forename: Nattaya
authors.initials: N
authors.lastname: Sae-Ung
authors.forename: Supan
authors.initials: S
authors.lastname: Fucharoen
mesh_terms: D000483:Alleles; D015331:Cohort Studies; D004909:Erythrocyte Indices; D005260:Female; D005319:Fetal Hemoglobin / Q000032:analysis* / Q000737:chemistry; D005817:Genetic Counseling; D018740:Genetic Heterogeneity; D005838:Genotype; D005914:Globins / Q000737:chemistry / Q000235:genetics*; D006443:Hemoglobin A2 / Q000032:analysis* / Q000737:chemistry; D006579:Heterozygote; D006801:Humans; D008297:Male; D009154:Mutation; D010641:Phenotype; D016133:Polymerase Chain Reaction; D013785:Thailand; D017085:alpha-Thalassemia / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics*; D017086:beta-Thalassemia / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics*
chemical_list: D005914:Globins; D006443:Hemoglobin A2; D005319:Fetal Hemoglobin