Subtype Distribution and Mutation Spectrum of Thalassemia in Children Under 10 Years in Northern Vietnam

Thalassemia is a common hereditary hemoglobin disorder in Vietnam. Elucidating the epidemiological and genetic patterns in children is essential for developing screening and prevention strategies.

A retrospective analysis of 1,240 children under 10 years of age with Thalassemia treated at the National Institute of Hematology and Blood Transfusion in Vietnam, between 2014 and 2023.

The median age at treatment initiation was 1 year (range 0-9 years), with 94.5% of patients aged 0-5 years. Children born after 2020 were diagnosed and treated earlier than those born before 2020 (0 year (range 0-2 years) vs 1 year (range 0-9 years); p < 0.0001), concurrent with the implementation of the national prenatal screening program. β-thalassemia and β-thalassemia/HbE accounted for nearly 90% of cases, with subtype distribution varying by ethnicity and region. β-thalassemia/HbE predominated in the Northwest and North Central regions, particularly among the Thai and Muong populations. In contrast, β-thalassemia was more prevalent in the Northeast, notably among the Tay and Nung populations. Eight α-globin and thirteen β-globin mutated types were detected. The common β-globin variants (CD17, CD41/42, CD71/72, -28, and IVSI-1) and HbE (CD26) mirror patterns reported in neighboring Laos and Guangxi Province, China. For α-globin genotypes, --^SEA (49.83%), Hb CS (31.53%), and -α^3.7 (8.47%) were most frequent.

Geography, ethnicity, and genetic background strongly shape Thalassemia epidemiology in Northern Vietnam. Targeted genetic counseling, early carrier screening, and region-focused community programs are urgently needed to reduce disease burden in high-risk populations.