The Natural History of Hb S/Hereditary Persistence of Fetal Hemoglobin in 13 Children from the State of Minas Gerais, Brazil

Abstract

Children with Hb S (HBB: c.20A > T)/hereditary persistence of fetal hemoglobin (Hb S/HPFH) have a mild clinical phenotype, but some complications have been reported. The natural history of Hb S/HPFH in children from the State of Minas Gerais, Brazil newborn cohort is described. Clinical and hematological data regarding participants’ phenotypes were retrieved from medical records. The HPFH-1, HPFH-2, and HPFH-3 and α-thalassemia (α-thal) deletions were detected by gap-polymerase chain reaction (gap-PCR). Thirteen children were included, nine (69.2%) had the Hb S/HPFH-2 deletion, and four (30.8%) had Hb S/HPFH-1 deletion; 11 children (84.6%) had αα/αα, and two (15.4%) carried the αα/−α^3.7 (rightward) deletion. The mean concentration of total hemoglobin (Hb) and Hb F was 12.52 ± 0.56 g/dL and 42.31% ± 1.97%, respectively. Mild microcytosis and hypochromia were observed. We found acute clinical manifestations of sickle cell disease, such as acute chest syndrome (ACS) and acute pain crisis in four children; nine (69.2%) children were completely asymptomatic during the follow-up period. All children were classified as having low-risk transcranial Doppler (TDC). In conclusion, children with Hb S/HPFH have a mild clinical phenotype of sickle cell disease, although acute clinical manifestations may occur. High Hb F levels and absence of anemia are common hematological characteristics.

• Hereditary persistence of fetal hemoglobin (HPFH)
• natural history
• sickle cell disease
• transcranial Doppler (TDC) ultrasonography

Acknowledgments

The authors acknowledge all subjects and parents for their cooperation in this study.

Declaration of interest

The authors thank the financial support of Fundação Hemominas, Núcleo de Ações e Pesquisa em Apoio Diagnóstico (NUPAD), Fundação de Amparo à Pesquisa de Minas Gerais (FAPEMIG; grant #PPM-00266-13), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq; grant #304530/2011-5), and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES). The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.