Family screening for HBB*S gene and detection of new cases of sickle cell trait in Northeastern Brazil

• Autor(a) principal: Bandeira, Flavia Miranda Gomes C
• Data de Publicação: 2008
• Outros Autores: Santos, Magnun Nueldo Nunes, Bezerra, Marcos André M, Gomes, Yara M, Araujo, Aderson Silva, Braga, Maria Cynthia, Souza, Wayner Vieira, Abath, Frederico G C
• Tipo de documento: Artigo
• Idioma: por; eng
• Título da fonte: Revista de Saúde Pública
• Texto Completo: https://www.revistas.usp.br/rsp/article/view/32404
• topic: Anemia Falciforme^i1^sepidemiolo; Traço Falciforme^i1^sepidemiolo; Detecção de Heterozigoto; Triagem Neonatal; Triagem Genética; Estudos Transversais; Anemia; Sickle Cell^i2^sepidemiol; Sickle Cell Trait^i2^sepidemiol; Heterozygote Detection; Neonatal Screening; Genetic Screening; Cross-Sectional Studies

OBJECTIVE: To estimate the additional number of affected individuals based on the prevalence of sickle-cell syndromes among relatives of index cases. METHODS: Cross-sectional study of relatives of a random sample of index cases identified through a neonatal screening program in Northeastern Brazil, between 2001 and 2005. The extended family trial model included 463 relatives of 21 index cases. Relatives were classified as nuclear family (NF: father, mother, and siblings); first degree extended family (N1: grandparents, uncles and aunts, and first cousins); second degree extended family (N2: children of first cousins); extended family (NA: NF+N1+N2); and extended nuclear family (NA1: NF+N1). The presence of HBB*S and other abnormal hemoglobins was confirmed by high-performance liquid chromatography. The association between the presence of HBB*S and other variables was calculated using prevalence ratios and their respective 95% confidence intervals, and differences between means were calculated using Student's t test with a 5% significance level. RESULTS: Of relatives, 81% had no knowledge of sickle-cell anemia and HBB*S was present in 114 family members. A total of 53.3% of the studied population was considered as of reproductive age, and 80% of HBB*S carriers had already had children. Frequency was higher among NF (69%), but was also high in N1 (22.8%). NA1 screening resulted in the detection of 69 carriers additional (a 172% increase). CONCLUSIONS: These results indicate that family screening for the identification of sickle-cell carriers should be extended to first degree relatives.