Clinical, laboratory, and molecular characteristics of a cohort of children with hemoglobinopathy S/beta-thalassemia

Érica Louback Oliveira; André Rolim Belisário; Natiely Pereira Silva; Paulo Val Rezende; Maristela Braga Muniz; Larissa Maira Moura Oliveira; Cibele Velloso-Rodrigues; Marcos Borato Viana

doi:10.1016/j.htct.2023.11.002

Clinical, laboratory, and molecular characteristics of a cohort of children with hemoglobinopathy S/beta-thalassemia

Hematol Transfus Cell Ther. 2024 Apr-Jun;46(2):167-175. doi: 10.1016/j.htct.2023.11.002. Epub 2023 Dec 19.

Authors

Érica Louback Oliveira¹, André Rolim Belisário², Natiely Pereira Silva¹, Paulo Val Rezende³, Maristela Braga Muniz³, Larissa Maira Moura Oliveira¹, Cibele Velloso-Rodrigues⁴, Marcos Borato Viana⁵

Affiliations

¹ Faculdade de Medicina/Núcleo de Ações e Pesquisa em Apoio Diagnóstico (NUPAD), UFMG, Belo Horizonte, MG, Brazil.
² Centro de Tecidos Biológicos de Minas Gerais, Fundação Hemominas, Lagoa Santa, MG, Brazil.
³ Ambulatório do Hemocentro de Belo Horizonte, Fundação Hemominas, Belo Horizonte, MG, Brazil.
⁴ Departamento de Ciências Básicas da Vida, Instituto de Ciências da Vida, Universidade Federal de Juiz de Fora, Governador Valadares, MG, Brazil.
⁵ Faculdade de Medicina/Núcleo de Ações e Pesquisa em Apoio Diagnóstico (NUPAD), UFMG, Belo Horizonte, MG, Brazil. Electronic address: vianamb@gmail.com.

PMID: 38182466
DOI: 10.1016/j.htct.2023.11.002

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 β^S-haplotypes were CAR and Benin. The most frequent β^thal-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. β^S-haplotypes and α-thalassemia did not meaningfully influence the phenotype of children with HbSβ-thal.

Conclusion: The early identification of β-thalassemia alleles may help the clinical management of these children.

Keywords: Alpha-thalassemia; Hemoglobin Sβ(+)-thalassemia; Hemoglobin Sβ(0)-thalassemia; Hemoglobin Sβ-thalassemia; Sickle cell disease.