Clinical, laboratory, and molecular characteristics of a cohort of children with hemoglobinopathy S/betathalassemia

• Published in: Hematology, transfusion and cell therapy Vol. 46; no. 2; pp. 167 - 175
• Main Authors: Oliveira, Érica Louback, Belisário, André Rolim, Silva, Natiely Pereira, Rezende, Paulo Val, Muniz, Maristela Braga, Oliveira, Larissa Maira Moura, Velloso-Rodrigues, Cibele, Viana, Marcos Borato
• Format: Journal Article
• Language: Portuguese
• Published: Associação Brasileira de Hematologia, Hemoterapia e Terapia Celular (ABHH) 2024
• Subjects: MEDICINE, GENERAL & INTERNAL; Hemoglobin Sβ0-thalassemia; Alpha-thalassemia; Hemoglobin Sβ-thalassemia; Hemoglobin Sβ+-thalassemia; Sickle cell disease
• DOI: 10.1016/j.htct.2023.11.002
• ISSN: 2531-1387

ABSTRACT Introduction: Hemoglobinopathy Sβ-thalassemia (HbSβ-thal) has a wide range of clinical and laboratory severity. There is limited information on the natural history of HbSβ-thal and its modulating factors. We described the molecular, hematological, and clinical characteristics of a cohort of children with HbSβ-thal and estimated its incidence in Minas Gerais, Brazil. Methods: Laboratory and clinical data were retrieved from medical records. Molecular analysis was performed by HBB gene sequencing, PCR-RFLP, gap-PCR, and MLPA. Results: Eighty-nine children were included in the study. Fourteen alleles of β-thal mutations were identified. The incidence of HbSβ-thal in the state was 1 per 22,250 newborns. The most common βS-haplotypes were CAR and Benin. The most frequent βthal-haplotypes were V, II, and I. Coexistence of 3.7 kb HBA1/HBA2 deletion was present in 21.3 % of children. β-thalassemia mutations were associated with several clinical and laboratory features. In general, the incidence of clinical events per 100 patient-years was similar for children with HbSβ0-thal, IVS-I-5 G>A, and IVS-I-110 G>A. Children with HbSβ+-intermediate phenotypes had a more severe laboratory and clinical profile when compared with those with HbSβ+-mild ones. βS-haplotypes and α-thalassemia did not meaningfully influence the phenotype of children with HbSβ-thal. Conclusion: The early identification of b-thalassemia alleles may help the clinical management of these children. © 2023 Associação Brasileira de Hematologia, Hemoterapia e Terapia Celular. Published by Elsevier España, S.L.U. This is an open access article under the CC BY-NC-ND license