Sickle cell disease: acute clinical manifestations in early childhood and molecular characteristics in a group of children in Rio de Janeiro

Abstract

ObjectivesTo describe clinical events of sickle cell disease and the correlation with β-globin haplotypes and α-thalassemia in under 6-year-old children.MethodsA retrospective study was conducted of under 6-year-old children from the neonatal screening program in Rio de Janeiro. Forty-eight male and 48 female children were enrolled in this study, 79 with sickle cell anemia and 17 with hemoglobin SC. The mean age was 29.9 (standard deviation = 20.9) months, 62 (16.2 ± 8.6) were aged between 0-3 years old and 34 (54.9 ± 11.3) were from 3-6 years old. Painful events, acute splenic sequestration, hemolytic crises, hand-foot and acute chest syndromes and infections were evaluated.ResultsThe events were more frequent in under 3-year-old children, 94% of children had at least one episode. Infection was the most common event affecting 88.5% of children. Acute splenic sequestration took place earlier, while painful crises and acute chest syndromes in under 6-year-old children. Thal-α 3.7 was observed in 20.9% of cases. Bantu was the most frequent haplotype found, followed by Benin. No correlation was observed between clinical events and β-globin haplotypes. Children with sickle cell anemia and α-thalassemia have less infectious events. No correlation was found among these polymorphisms and clinical events, however, the majority of children with Bantu/Bantu and without α-thalassemia had more clinical events.

Sickle cell anemia: clinical diversity and beta S-globin haplotypes

“…Brazilian studies also found a correlation between SCA clinical manifestations, Hb Fand the beta S-globin haplotype ( 8 , 9 , 13 , 19 , 25 , 29 , 30 ) , including more vaso-occlusive crises ( 9 , 29 ) , more infections ( 9 ) and slower growth ( 29 ) in the CAR haplotype, high levels of Hb F ( 13 , 19 , 25 ) and nitrites in the BEN haplotype ( 19 ) , and increased risk of cerebro vascular disease (CVD) in children with the Bantu/atypical haplotype compared to other beta S-globin haplotypes ( 30 ) . Patients with the CAR/BEN haplotype had less painful crises compared to the other haplotypes ( 22 ) .…”

“…Patients with the CAR/BEN haplotype had less painful crises compared to the other haplotypes ( 22 ) . Trials have shown no correlations between co-inheritance with alpha-thalassemia and clinical symptoms ( 8 , 9 , 22 ) , however it may be associated with less infections ( 13 ) or with repeated acute pain crises ( 29 ) .…”

“…Painful crises, ASS, hemolytic crises, hand-foot syndromes, ACS and infections were not related to the beta S-globin haplotype in another retrospective study of under 6-year-old children. Nevertheless, this lack of correlation could be due to the sample size, the number of heterozygous individuals, the miscegenation of the Brazilian population, and the multiplicity of the clinical expression in SCA ( 13 ) . It was not reported in these papers whether the patients (or how many patients) were receiving hydroxyurea (HU).If HU was being administered to SCA patients with the worst clinical symptoms, presumably those with the CAR haplotype, would this not explain the lack of clinical correlations between different beta S-globin haplotypes?…”

Beta-S globin haplotypes in patients with sickle cell anemia: one approach to understand the diversity in Brazil

“…Data from genotype and allele frequencies are shown in Table 1. The high frequencies of Bantu and Benin haplotypesdemonstrate the influence of Western and South-Central African on the evolution of the Brazilian population (6) . We identified atypical haplotypes which may have originated due togenetic mechanisms such as gene conversions and the intense miscegenation between ethnicgroups that inhabit Rio de Janeiro State and Brazil.…”

Anemia Falciforme: Caracterização Dos Pacientes Atendidos Em Um Ambulatório De Referência

“…Este evento requer intervenção imediata, pois pode evoluir para choque hipovolêmico. A esplenectomia, que representou 17,24% de todas as causas de internação, é o tratamento terapêutico para esta complicação clínica, indicada após duas crises de sequestração esplênica ou após o primeiro episódio grave (15,10,21) . A palidez cutânea acometendo quase a totalidade dos pacientes com AF, geralmente está associada à icterícia, dispneia, astenia e intolerância a atividade física.…”