β‐Hemoglobinopathies in the Lao People's Democratic Republic: Molecular diagnostics and implication for a prevention and control program.

Introduction: A high frequency of β‐thalassemia in Lao People's Democratic Republic necessitates the importance of complete molecular data before a prevention and control program could be established. Limited data are available for Lao PDR. We have now reported an extended information on the molecular basis of β‐hemoglobinopathies in this population. Methods: The study was done on 519 unrelated Laos subjects requested for thalassemia investigation. Hematological data were recorded. Hb profiles were obtained using a capillary electrophoresis system. α‐And β‐globin genotyping was performed using PCR and related techniques. Results: Among the 519 subjects, 287 (55.3%) were found to carry β‐hemoglobinopathies based on Hb and DNA analyses. These included Hb E carriers (n = 135), homozygous Hb E (n = 47), β‐thalassemia carriers (n = 70), Hb E‐β‐thalassemia (n = 25), homozygous β‐thalassemia (n = 4), heterozygous δβ0‐thalassemia (n = 2), and carriers of the β‐Hb variant (n = 3). Mutation analysis identified in addition to the Hb E, 8 different β‐thalassemia mutations including codon 17 (A‐T), codons 41/42 (‐TTCT), NT‐28 (A‐G), codons 71/72 (+A), IVS1‐1 (G‐T), 3.4 kb deletion, an initiation codon (T‐G) and IVS2‐654 (C‐T). Two δβ0‐thalassemia carriers (12.6 kb deletion) and three subjects with Hb Hope (β136GGT‐GAT) were identified. Hematological features associated with these β‐hemoglobinopathies were presented. Conclusion: β‐hemoglobinopathies in the Laos population is heterogeneous. This information is relevant for setting up a molecular diagnostics and can provide a basis for genetic counseling and enable prenatal diagnosis. [ABSTRACT FROM AUTHOR]