Triagem neonatal para hemoglobinopatias: experiência de um ano na rede de saúde pública do Rio Grande do Sul, Brasil

Abstract

Hemoglobinopathies are the most common inherited disorders in humans; the most frequent are hemoglobins S and C (Hb S and Hb C). Studies in Brazil show the high prevalence of Hb S and Hb C heterozygotes, indicating the need for diagnosis to allow medical care and suitable genetic counseling. This study evaluates the prevalence of hemoglobin patterns in different areas of Rio Grande do Sul State, Brazil, using neonatal data from the public health system. Blood samples from 117,320 newborns, obtained by heel stick, and 2,389 blood samples from parents of newborns, obtained by venopuncture, were submitted to IEF and HPLC. Among the newborns, 1,629 (1.4%) showed abnormal hemoglobin patterns: 1,342 FAS; 225 FAC; 45 FAD; 2 FSC; 1 FS and 26 variant hemoglobin heterozygotes. We conclude that the methods used are able to identify a broad variety of hemoglobin patterns with high specificity and sensitivity. The information is of paramount importance for transmitting knowledge in the public health field, besides facilitating planning and resource allocation.

Phenylketonuria, congenital hypothyroidism and haemoglobinopathies: public health issues for a Brazilian newborn screening program

“…In 2007, incidence of sickle cell disease in Rio de Janeiro, was 1:1,288 (Table 1), compared to 1:650 in the State of Bahia which has the highest incidence rate for this disease in Brazil 21 . Although not directly comparable, the data regarding prevalence of sickle cell disease in Rio Grande do Sul (1:39,000) was consistent with the lower proportion of African descendants in that state 24 .…”

Prevalência da hemoglobina S no Estado do Paraná, Brasil, obtida pela triagem neonatal

“…Em relação às 15 crianças com interação Sβ-talassemia, a nove delas foi atribuída cor branca (60%), a três, cor parda (20%), e a três, cor negra (20% 20 , sendo que a estimativa da freqüência alélica de HbS (0,63%) não difere da encontrada no presente estudo de 0,76% (p > 0,05). Em 117.320 recém-nascidos do Rio Grande do Sul, foram encontrados apenas um caso de anemia falciforme e 1,14% de heterozigotos, e a freqüência alélica de 0,57% de HbS é, significativamente, menor que a do presente estudo (p < 0,0001) 21 . Os dados de freqüências alélicas de HbS encontrados para a Bahia 22 , Pernambuco 23 e Minas Gerais 17 foram, significativamente, mais altos do que os da presente investigação (p < 0,0001).…”

Investigação bibliográfica sobre a hemoglobina S de 1976 a 2007

“…However, by analyzing DNA polymorphisms in the hemoglobin's â gene complex in 30 patients with sickle cell anemia in the population of the city of Belém, capital of the state of Pará, only 3% were found to have the Senegal haplotype; 30%, the Benin haplotype; and 67%, the Bantu haplotype. Regional differences in the origin of African slaves were changed by the domestic slave traffic and, subsequently, by migratory movements, as observed by the prevalence of 1.14% of sickle cell traits in the state of Rio Grande do Sul, in Southern Brazil (17)(18) . In Brazil, sickle cell anemia is the most prevalent hereditary disease, affecting between 0.1% and 0.3% of the black population and with a tendency to affect significantly higher numbers of individuals in the population, due to the high level of miscegenation (16) .…”