Consulta: subjectFacets:"Alpha-thalassemia"
Registros recuperados: 6
Data/hora: 02/06/2024 00:35:04

Prevalence of common α-thalassemia determinants in south Brazil: importance for the diagnosis of microcytic anemia
Provedor de dados: 74
Autores: Wagner,Sandrine C.; Castro,Simone M. de; Gonzalez,Tatiana P.; Santin,Ana P.; Filippon,Leticia; Zaleski,Carina F.; Azevedo,Laura A.; Amorin,Bruna; Callegari-Jacques,Sidia M.; Hutz,Mara H.
Alpha thalassemia has not been systematically investigated in Brazil. In this study, 493 unrelated individuals from the southernmost Brazilian state of Rio Grande do Sul were screened for deletional forms of α-thalassemia. One hundred and one individuals had microcytic anemia (MCV &lt; 80 fL) and a normal hemoglobin pattern (Hb A2 &lt; 3.5% and Hb F &lt; 1%). The subjects were screened for -α3.7,-α4.2,-α20.5, -SEA and -MED deletions but only the -α3.7 allele was detected. The -α3.7 allele frequency in Brazilians of European and African ancestry was 0.02 and 0.12, respectively, whereas in individuals with microcytosis the frequency was 0.20. The prevalence of α-thalassemia was significantly higher in individuals with microcytosis than in healthy individuals...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Alpha-thalassemia; Brazilian population; Genotype; Hemoglobin; Microcytosis.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572010000400008

Prevalence of α-thalassemia 3.7 kb deletion in the adult population of Rio Grande do Norte, Brazil
Provedor de dados: 74
Autores: Alcoforado,Gustavo Henrique de Medeiros; Bezerra,Christiane Medeiros; Lemos,Telma Maria Araújo Moura; Oliveira,Denise Madureira de; Kimura,Elza Miyuki; Costa,Fernando Ferreira; Sonati,Maria de Fátima; Medeiros,Tereza Maria Dantas de.
α-Thalassemia, arising from a defect in a-globin chain synthesis, is often caused by deletions involving one or both of the a-genes on the same allele. With the aim of investigating the prevalence of α-thalassemia 3.7 kb deletion in the adult population of Rio Grande do Norte, 713 unrelated individuals, between 18 and 59 years-of-age, were analyzed. Red blood cell indices were electronically determined, and A2 and F hemoglobins evaluated by HPLC. PCR was applied to the molecular investigation of α-thalassemia 3.7 kb deletion. Eighty (11.2%) of the 713 individuals investigated presented α-thalassemia, of which 79 (11.1%) were heterozygous (-α3.7/αα) deletions and 1 (0.1%) homozy- gous (-α3.7/-α3.7). Ethnically, heterozygous deletions were higher (24.8%) in...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Alpha-thalassemia; -α3.7 kb deletion; Brazilian population.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572012000400008

Hb H disease resulting from the association of an αº-thalassemia allele [-(α)20.5] with an unstable α-globin variant [Hb Icaria]: first report on the occurrence in Brazil
Provedor de dados: 74
Autores: Kimura,Elza M.; Oliveira,Denise M.; Fertrin,Kleber; Pinheiro,Valéria R.; Jorge,Susan E.D.C.; Costa,Fernando F.; Sonati,Maria de Fátima.
Hb H Disease is caused by the loss or inactivation of three of the four functional a-globin genes. Patients present chronic hemolytic anemia and splenomegaly. In some cases, occasional blood transfusions are required. Deletions are the main cause of this type of thalassemia (α-thalassemia). We describe here an unusual case of Hb H disease caused by the combination of a common αº deletion [-(α)20.5] with a rare point mutation (c.427T &gt; A), thus resulting in an elongated and unstable α-globin variant, Hb Icaria, (X142K), with 31 additional amino-acid residues. Very high levels of Hb H and Hb Bart's were detected in the patient's red blood cells (14.7 and 19.0%, respectively). This is the first description of this infrequent association in the Brazilian...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Hereditary hemoglobinopathies; Alpha-thalassemia; Hb H disease; Hb Icaria.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572009000400007

Characterization of alpha thalassemic genotypes by multiplex ligation-dependent probe amplification in the Brazilian population
Provedor de dados: 56
Autores: Suemasu,C.N.; Kimura,E.M.; Oliveira,D.M.; Bezerra,M.A.C.; Araújo,A.S.; Costa,F.F.; Sonati,M.F.
Alpha-thalassemia is the most common inherited disorder of hemoglobin synthesis. Genomic deletions involving the alpha-globin gene cluster on chromosome 16p13.3 are the most frequent molecular causes of the disease. Although common deletions can be detected by a single multiplex gap-PCR, the rare and novel deletions depend on more laborious techniques for their identification. The multiplex ligation-dependent probe amplification (MLPA) technique has recently been used for this purpose and was successfully used in the present study to detect the molecular alterations responsible for the alpha-thalassemic phenotypes in 8 unrelated individuals (3 males and 5 females; age, 4 months to 30 years) in whom the molecular basis of the disease could not be determined...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Alpha-thalassemia; Hb H disease; Multiplex ligation-dependent probe amplification; Genetic polymorphisms; Brazilian population.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2011000100003

alpha-Globin genes: thalassemic and structural alterations in a Brazilian population
Provedor de dados: 56
Autores: Wenning,M.R.S.C.; Kimura,E.M.; Costa,F.F.; Saad,S.T.O.; Gervásio,S.; de Jorge,S.B.; Borges,E.; Silva,N.M.; Sonati,M.F.
Seven unrelated patients with hemoglobin (Hb) H disease and 27 individuals with alpha-chain structural alterations were studied to identify the alpha-globin gene mutations present in the population of Southeast Brazil. The -alpha3.7, --MED and -(alpha)20.5 deletions were investigated by PCR, whereas non-deletional alpha-thalassemia (alphaHphalpha, alphaNcoIalpha, &lt;FONT FACE="Symbol"&gt;aa&lt;/FONT&gt;NcoI, alphaIcalpha and alphaTSaudialpha) was screened with restriction enzymes and by nested PCR. Structural alterations were identified by direct DNA sequencing. Of the seven patients with Hb H disease, all of Italian descent, two had the -(alpha)20.5/-alpha3.7 genotype, one had the --MED/-alpha3.7 genotype, one had the --MED/alphaHphalpha genotype and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Alpha-globin genes; Alpha-globin structural variants; Alpha-thalassemia; Hemoglobin H; Hb H disease; Hemoglobin variants; Hemoglobinopathies.
Ano: 2000
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2000000900008

High prevalence of alpha-thalassemia among individuals with microcytosis and hypochromia without anemia
Provedor de dados: 56
Autores: Borges,E.; Wenning,M.R.S.C.; Kimura,E.M.; Gervásio,S.A.; Costa,F.F.; Sonati,M.F.
In order to determine the contribution of alpha-thalassemia to microcytosis and hypochromia, 339 adult outpatients seen at Unicamp University Hospital (with the exception of the Clinical Hematology outpatient clinics), who showed normal hemoglobin (Hb) levels and reduced mean corpuscular volume and mean corpuscular hemoglobin, were analyzed. Ninety-eight were Blacks (28.9%) and 241 were Caucasians (71.1%). In all cases, Hb A2 and F levels were either normal or low. The most common deletional and nondeletional forms of alpha-thalassemia [-alpha3.7, -alpha4.2, --MED, -(alpha)20.5, alphaHphIalpha, alphaNcoIalpha, &lt;FONT FACE="Symbol"&gt;aa&lt;/FONT&gt;NcoI and alphaTSAUDI] were investigated by PCR and restriction enzyme analyses. A total of 169 individuals...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Alpha-thalassemia; Microcytosis; Hypochromia; Hemoglobinopathies; Brazilian population.
Ano: 2001
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2001000600009