A large cohort of β(+)-thalassemia in Thailand: molecular, hematological and diagnostic considerations.

Abstract

We report the molecular and hematological characteristics associated with a large cohort of β(+)-thalassemia in Thailand. Study was done on 21,068 unrelated subjects referred to our center in northeast Thailand for hemoglobinopathies investigation. Among 21,068 subjects, 2637 (12.5%) were found to carry β-thalassemia. Of these 2637 cases, 705 (26.7%) carried β(+)-thalassemia with eight different mutations including 6 promoter mutations; NT-28 (A-G), NT-31 (A-G), NT-50 (G-A), NT-86 (C-G), NT-87 (C-A) and NT-90 (C-T) and two missense mutations; Hb Malay (codon 19; AAC-AGC) and Hb Dhonburi (codon 126; GTG-GGG). Hematological features of carriers with these β(+)-thalassemia (n=528) were compared with those with β(0)-thalassemia (n=309). Data for Hb E-β(+)-thalassemia (n=177) were also presented along with Hb E-β(0)-thalassemia in our series (n=94). All patients with Hb E-β(+)-thalassemia were associated with mild thalassemia intermedia phenotypes. Most of the β(+)-thalassemia carriers had elevated Hb A2 and mild hypochromic microcytosis, some demonstrated borderline MCV and MCH values which, could compromise carrier screening. Analysis of α/β-globin mRNA ratio in representative cases with normal, Hb E trait, β(+)-thalassemia trait, Hb Dhonburi trait and β(0)-thalassemia trait demonstrated the average values of 1.1, 1.7, 2.1, 1.7 and 3.1, respectively which is helpful in identification and differentiation of the cases.

• Authors: Supawadee Yamsri, Kritsada Singha, Thanet Prajantasen, Wachiraporn Taweenan, Goonnapa Fucharoen, Kanokwan Sanchaisuriya, Supan Fucharoen
• Journal: Blood cells, molecules & diseases (Blood Cells Mol Dis) Vol. 54 Issue 2 Pg. 164-9 (Feb 2015) ISSN: 1096-0961 [Electronic] United States
• PMID: 25471338 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2014 Elsevier Inc. All rights reserved.

Chemical References

• Codon
• Hemoglobins, Abnormal
• alpha-Globins
• beta-Globins
• hemoglobin Malay
• hemoglobin Dhonburi
• Hemoglobin A2
• Hemoglobin E

Topics

• Codon
• Cohort Studies
• Female
• Genetic Heterogeneity
• Genetic Testing
• Genotype
• Hemoglobin A2 (genetics)
• Hemoglobin E (genetics)
• Hemoglobins, Abnormal (genetics)
• Humans
• Male
• Mutation
• Phenotype
• Promoter Regions, Genetic
• Thailand
• alpha-Globins (genetics)
• beta-Globins (genetics)
• beta-Thalassemia (genetics, pathology)