SABIIA - Sistema Aberto e Integrado de Informação em Agricultura (Sabiia)

Barbosa,C.G.; Goncalves-Santos,N.J.; Souza-Ribeiro,S.B.; Moura-Neto,J.P.; Takahashi,D.; Silva,D.O.; Hurtado-Guerrero,A.F.; Reis,M.G.; Goncalves,M.S..

Fetal hemoglobin (HbF), encoded by the HBG2 and HBG1 genes, is the best-known genetic modulator of sickle cell anemia, varying dramatically in concentration in the blood of these patients. This variation is partially associated with polymorphisms located in the promoter region of the HBG2 and HBG1 genes. In order to explore known and unknown polymorphisms in these genes, the sequences of their promoter regions were screened in sickle cell anemia patients and correlated with both their HbF levels and their βS-globin haplotypes. Additionally, the sequences were compared with genes from 2 healthy groups, a reference one (N = 104) and an Afro-descendant one (N = 98), to identify polymorphisms linked to the ethnic background.The reference group was composed by...

Effect of hydroxyurea on G gamma chain fetal hemoglobin synthesis by sickle-cell disease patients

Palavras-chave: Fetal hemoglobin; Sickle cell anemia; HBG1 gene; HBG2 gene.

Ano: 2010

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2010000800002

Teixeira,S.M.; Cortellazzi,L.C.; Grotto,H.Z.W..

Hydroxyurea is used for sickle-cell disease patients in order to increase fetal hemoglobin synthesis and consequently decrease the severity of pain episodes. Fetal hemoglobin, which is formed by gamma-globin chains A and G, is present in a constant composition throughout fetal development: about 75% of Ggamma and 25% of Agamma. In contrast, adult red cells contain about 40% of Ggamma and 60% of Agamma. In the present study, we analyzed the effect of hydroxyurea induction on the gamma chain composition of fetal hemoglobin in 31 sickle-cell disease patients treated with hydroxyurea. The control group was composed of 30 sickle-cell disease patients not treated with hydroxyurea in clinical steady state. The patients were older than 13 years and were not...

The Agamma-195 (C->G) mutation in hereditary persistence of fetal hemoglobin is not associated with activation of a reporter gene in vitro

Palavras-chave: Gamma chain; Fetal hemoglobin; Hydroxyurea; Sickle-cell disease.

Ano: 2003

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2003001000002

Schreiber,R.; Gonçalves,M.S.; Junqueira,M.L.; Saad,S.T.O.; Krieger,J.E.; Costa,F.F..

Hereditary persistence of fetal hemoglobin is an uncommon, benign disorder in which the expression of gamma-globin genes persists into adult life. Several point mutations have been associated with the increased gamma-globin gene promoter activity. We evaluated the -195 (C->G) mutation by a functional in vitro assay based on the luciferase reporter gene system. The results indicated that the increased promoter activity observed in vivo could not be reproduced in vitro under the conditions employed, suggesting that other factors may be involved in the overexpression of the gamma-globin gene containing the -195 (C->G) mutation. Furthermore, this is the first time that the -195 (C->G) mutation of the Agamma-globin gene has been evaluated by in vitro...

Sequence change in the HS2-LCR and Gg-globin gene promoter region of sickle cell anemia patients

Palavras-chave: Fetal hemoglobin; Hereditary persistence of fetal hemoglobin; HPFH; Transient expression.

Ano: 2001

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2001000400008

Adorno,E.V.; Moura-Neto,J.P.; Lyra,I.; Zanette,A.; Santos,L.F.O.; Seixas,M.O.; Reis,M.G.; Goncalves,M.S..

The fetal hemoglobin (HbF) levels and ßS-globin gene haplotypes of 125 sickle cell anemia patients from Brazil were investigated. We sequenced the Gg- and Ag-globin gene promoters and the DNase I-2 hypersensitive sites in the locus control regions (HS2-LCR) of patients with HbF level disparities as compared to their ßS haplotypes. Sixty-four (51.2%) patients had CAR/Ben genotype; 36 (28.8%) Ben/Ben; 18 (14.4%) CAR/CAR; 2 (1.6%) CAR/Atypical; 2 (1.6%) Ben/Cam; 1 (0.8%) CAR/Cam; 1 (0.8%) CAR/Arab-Indian, and 1 (0.8%) Sen/Atypical. The HS2-LCR sequence analyses demonstrated a c.-10.677G>A change in patients with the Ben haplotype and high HbF levels. The Gg gene promoter sequence analyses showed a c.-157T>C substitution shared by all patients, and a...

Increased fetal hemoglobin levels in patients infected with human immunodeficiency virus (HIV1/2)

Palavras-chave: Fetal hemoglobin; Sickle cell anemia; SSS-globin gene haplotypes; Locus control region; G-globin promoter.

Ano: 2008

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2008000200003

Poli-Neto,A.; Nonoyama,K.; Oshiro,M.; Ebner-Filho,W.; Miguita,K.; Medeiros,T.M.D.; Watanabe,C.I.; Barretto,O.C.O..

Fetal hemoglobin was measured in HIV1/2 patients under treatment with combined therapy (zidovudine and a protease inhibitor). A total of 143 patients and 103 normal individuals were investigated by the quantitative method of Betke and the semi-quantitative acid elution method of Kleihauer. In the normal person, hemoglobin F makes up less than 1% and an increase higher than 1.5% was observed in 21.4% of HIV patients by the method of Betke and in 24.8% of HIV-infected patients by the method of Kleihauer. The quantitative biochemical method of Betke showed that the populations were significantly different (two-tailed Mann-Whitney test). The reason for this hemoglobin F increase might be ascribed to the effect of zidovudine or to direct viral action on gamma...

ßS-Haplotypes in sickle cell anemia patients from Salvador, Bahia, Northeastern Brazil

Palavras-chave: Human immunodeficiency virus; HIV1/2; Hemoglobin; Fetal hemoglobin; F cells; Zidovudine.

Ano: 2000

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2000001100008

Gonçalves,M.S.; Bomfim,G.C.; Maciel,E.; Cerqueira,I.; Lyra,I.; Zanette,A.; Bomfim,G.; Adorno,E.V.; Albuquerque,A.L.; Pontes,A.; Dupuit,M.F.; Fernandes,G.B.; Reis,M.G. dos.

ßS-Globin haplotypes were studied in 80 (160 ßS chromosomes) sickle cell disease patients from Salvador, Brazil, a city with a large population of African origin resulting from the slave trade from Western Africa, mainly from the Bay of Benin. Hematological and hemoglobin analyses were carried out by standard methods. The ßS-haplotypes were determined by PCR and dot-blot techniques. A total of 77 (48.1%) chromosomes were characterized as Central African Republic (CAR) haplotype, 73 (45.6%) as Benin (BEN), 1 (0.63%) as Senegal (SEN), and 9 (5.63%) as atypical (Atp). Genotype was CAR/CAR in 17 (21.3%) patients, BEN/BEN in 17 (21.3%), CAR/BEN in 37 (46.3%), BEN/SEN in 1 (1.25%), BEN/Atp in 1 (1.25%), CAR/Atp in 6 (7.5%), and Atp/Atp in 1 (1.25%). Hemoglobin...

Fetal hemoglobin levels are related to metabolic control in diabetic subjects

Palavras-chave: Beta(S)-haplotypes; Fetal hemoglobin; Sickle cell anemia; S hemoglobin; Brazilian population.

Ano: 2003

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2003001000001

Pardini,V.C.; Victória,I.M.N.; Pieroni,F.B.; Milagres,G.; Nascimento,P.D.; Velho,G.; Purisch,S.; Pardini,H..

We have investigated the relationship between fetal hemoglobin (HbF) levels and metabolic control in subjects with insulin-dependent (N = 79) and non-insulin-dependent diabetes mellitus (N = 242). HbF and hemoglobin A1c (HbA1c) levels were increased in subjects with type 1 and type 2 diabetes as compared to levels in nondiabetic individuals (P<0.0001), and were significantly higher in type 1 than in type 2 diabetes subjects. Lower levels of HbA1c and HbF were observed in type 2 diabetes subjects treated by diet, intermediate levels in those treated with oral hypoglycemic agents, and higher levels in those treated with insulin. HbF and HbA1c levels were correlated in type 1 diabetes (R2 = 0.57, P<0.0001) and type 2 diabetes (R2 = 0.58,...

Genetic variants in the G gamma-globin promoter modulate fetal hemoglobin expression in the Colombian population

Palavras-chave: Fetal hemoglobin; HbA1c; Glycated hemoglobin; Diabetes mellitus; Type 1 diabetes; Type 2 diabetes.

Ano: 1999

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1999000600005

Genet. Mol. Biol.

Fong,Cristian; Mendoza,Yesica; Barreto,Guillermo.

Abstract Fetal hemoglobin (HbF) is a determining factor for the development of sickle cell anemia. High HbF levels lower the intensity of symptoms of this disease. HbF levels can vary in patients with sickle cell anemia and individuals without the disease. The purpose of this study was to identify the genetic variants in the G gamma-globin gene promoter that can modulate HbF expression in patients with sickle cell anemia and healthy individuals from Colombia. In total, 413 bp of the G gamma-globin gene promoter were sequenced in 60 patients with sickle cell anemia and 113 healthy individuals. The allelic and genotype frequencies of the identified variants were compared between individuals with low and high HbF for both patients and healthy individuals. In...

Clinical and molecular characteristics of sickle cell anemia in the northeast of Brazil

Palavras-chave: Sickle cell anemia; Fetal hemoglobin; Gamma globin; Regulation of gene expression; Colombia.

Ano: 2020

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572020000400103

Genet. Mol. Biol.

Adorno,Elisângela Vitória; Zanette,Ângela; Lyra,Isa; Seixas,Magda Oliveira; Reis,Mitermayer Galvão; Gonçalves,Marilda Souza.

Beta S-globin gene (βS-globin) haplotypes, markers for severe sickle cell anemia (SCA), and the alpha-thalassemia 2 gene 3.7 kb deletion (-α2(3.7 kb) thal) along with demographic and clinical data were investigated in SCA outpatients (n = 125, 63 female and 62 male) in the Brazilian state of Bahia, which has a high prevalence SCA. PCR-RFLP showed that the Central African Republic/Benin (CAR/BEN, 51.2%) haplotype was most frequent, followed by the Benin/Benin (Ben/Ben, 28.8%). At least one CAR haplotype was present in every outpatient with a history of cerebrovascular accident. The Cameroon (Cam), Senegal (Sen) and Arab-India haplotypes occurred in small numbers, as did atypical haplotypes. Fetal hemoglobin (HbF, %) was unevenly distributed. Compared to...