A doença falciforme: um estudo genético-populacional a partir de doadores de sangue em São José dos Campos, São Paulo, Brasil

Abstract

Sickle cell disease is a genetic disease that originated in several different regions, in particular African communities. The disease is present in the Brazilian population. The large number of heterozygotes and the severe clinical symptoms of homozygotes have drawn special attention from the government institutions in Brazil. Since the genetic origin of the disease was elucidated, sickle cell disease has become the focus of an every-growing number of scientific investigations. This investigation was performed to correlate the presence of the sickle cell trait in inhabitants of São José dos Campos, Brazil, with data on immigrants. The study sample consisted of 93,604 blood donors of the Hematology and Hemotherapy Service in São José dos Campos from 2004 to 2008. An analysis of the donors identified 400 heterozygous individuals with the sickle cell trait (Hb S-0.43%) but no homozygotes. The results are completely different from the national pattern and are strongly supported by local history.

Follow-up of children with hemoglobinopathies diagnosed by the Brazilian Neonatal Screening Program in the State of Pernambuco

“…Some studies highlight the importance of training health care professionals on how to responsibly and clearly inform parents so that conscious reproductive decisions can be taken. 28 , 29 , 30 …”

Patient with sickle cell anemia

“…In the following decade, the goal of many researchers, such as Ernani Martins da Silva, a scientist at the Oswaldo Cruz Institute, was to correlate the frequency of sickle red cells with Brazilian racial diversity, especially to identify the degree of miscegenation [18]. Sickle cell disease was discovered, however, its inheritance was only found by the study of physician José Accioly, in 1947 in Bahia, which characterized red blood cell sickling as a consequence of an autosomal dominant inheritance [19]. But it was in 1949 that James Van Gundia Neel proved it experimentally [20].…”

Prevalência de hemoglobina S em doadores de sangue do Hemocentro de Passo Fundo, Rio Grande do Sul, Brasil

“…As manifestações clínicas mais importantes dessa doença compreendem a anemia hemolítica crônica e obstruções nos vasos capilares, que provocam dor e, com o passar dos anos, lesões isquêmicas, que podem causar insuficiência renal, pulmonar, além de aumentar o risco de complicações cardiovasculares 3,4 . Essas manifestações ocorrem a partir do primeiro ano de vida e são responsáveis por consideráveis taxas de morbidade e mortalidade 5 .…”

“…Em afro-americanos e na Jamaica este número chega a 10% 9 . No Brasil, estudos demonstram que esta prevalência pode variar de 0,43% a 9,80%, dependendo da região do País 5,11 .…”

“…É possível sugerir que esta baixa prevalência da HbS esteja relacionada ao baixo número de descentes africanos na região. Estudo semelhante foi realizado em São José dos Campos/SP, onde a prevalência do traço falcêmico foi de 0,43%, em uma população com 78% de indivíduos leucodermas 5 . Também no estudo de Lidani et al 14 , no município de Curitiba/PR, encontrouse uma prevalência de HbS de 0,9% em doadores de um banco de sangue, e, entre os portadores do traço falcêmico, a maioria era declarada afro-brasileiros 14 .…”