Molecular and hematological characterization of thalassemia and hemoglobinopathies among pediatric patients in northern Lao People’s Democratic Republic

Abstract

Abstract Thalassemia and hemoglobinopathies are highly prevalent in the Lao People’s Democratic Republic (Lao PDR). Luang Prabang Province represents an ethnically diverse area with a high burden of pediatric anemia, but the molecular and hematological characteristics of thalassemia in this setting have not been systematically described. This hospital-based cross-sectional study included consecutive pediatric patients encountered at the Lao Friends Hospital for Children, Luang Prabang, between August and November 2025. Leftover EDTA-anticoagulated blood specimens and corresponding clinical data were analyzed. Hemoglobin analysis was performed using capillary zone electrophoresis, and molecular characterization of α- and β-globin gene defects was conducted using PCR-based assays. A total of 206 pediatric patients were recruited. β-thalassemia disease accounted for 51.9% of hospital presentations (n = 107), while 26.2% of patients had α-thalassemia diseases (n = 54), and the remaining cases comprised combined α- and β-thalassemia diseases (n = 38, 18.9%). Molecular analysis identified as many as 40 distinct thalassemia genotypes, indicating substantial genetic heterogeneity. Among α-thalassemia disease, non-deletional Hb H disease, predominantly associated with the -- SEA /α CS α genotype, was the most frequent presentation. Among β-thalassemia disease, β⁰/β E was the most common genotype. At the molecular level, hemoglobin E was the most frequent β-globin allele, followed by the codons 41/42 (-TTCT), codon 17 (A > T), and promoter − 28 mutations (A > G). Hematological findings demonstrated moderate to severe anemia across clinically significant thalassemia syndromes. The first hospital-based molecular and hematological characterization of pediatric thalassemia in northern Lao PDR demonstrates genotypic and phenotypic heterogeneities, with clinically significant β-thalassemia and non-deletional α-thalassemia. These findings provide important evidence to support more accurate diagnostic approaches and inform thalassemia screening and prevention strategies in Lao PDR.