Navegando por Assunto "Fator V Leiden"

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Acesso aberto (Open Access)
Discriminação alélica do fator V da coagulação por PCR em tempo real: diagnóstico simples e preciso
(2009-03) OLIVEIRA FILHO, Aldemir Branco de; CAMPOS, Júlia Furtado; LIMA, Magaly do Bom Parto Lopes Vieira; MELO, Fárida Coeli de Barros Correia; NEVES, Washington Batista das; MELO, Raul Antônio Morais; LEMOS, José Alexandre Rodrigues de
Among cardiovascular diseases, venous thrombosis is important due to the association between acquired and genetic risks factors. Hereditary resistance to activated protein C has been identified as the main cause of venous thrombosis, and is frequently associated to the factor V Leiden mutation (G1694A). In homozygotic individuals, the risk of venous thrombosis is 50 to 100 times higher that in normal patients, while in heterozygotic patients the risk is 5 to 10 times higher. Based on the need of evaluation and follow up of patients with venous thrombosis and prevention in their respective families, a simple method of allelic discrimination of coagulation V factor was developed using real time PCR. Sixty-seven patients with a history of venous thrombosis and 51 individuals without venous thrombosis were selected for this study. First, identification of the factor V allele was achieved through conventional PCR followed by enzymatic digestion (Mnl). Subsequently, diagnosis was attained by real time PCR. Both the methods investigated the G1691A polymorphism using VIC and FAM fluorophores to mark nucleotides G and A, respectively. By PCR-RFLP, 95 individuals were diagnosed as normal homozygotes, 21 as heterozygotes and 2 as homozygotic factor V Leiden individuals. The same results were obtained using real time PCR. Maximum similarity between the results of real time PCR and PCR-RFLP indicates high precision of the new method for allelic identification and visualization of factor V Leiden.
Acesso aberto (Open Access)
Increased risk of venous thrombosis by AB alleles of the ABO blood group and Factor V Leiden in a Brazilian population
(2009) LIMA, Magaly do Bom Parto Lopes Vieira; OLIVEIRA FILHO, Aldemir Branco de; CAMPOS, Júlia Furtado; MELO, Fárida Coeli de Barros Correia; NEVES, Washington Batista das; MELO, Raul Antônio Morais; LEMOS, José Alexandre Rodrigues de
Most cases of a predisposition to venous thrombosis are caused by resistance to activated protein C, associated in 95% of cases with the Factor V Leiden allele (FVL or R506Q). Several recent studies report a further increased risk of thrombosis by an association between the AB alleles of the ABO blood group and Factor V Leiden. The present study investigated this association with deep vein thrombosis (DVT) in individuals treated at the Hemocentro de Pernambuco in northeastern Brazil. A case-control comparison showed a significant risk of thrombosis in the presence of Factor V Leiden (OR = 10.1), which was approximately doubled when the AB alleles of the ABO blood group were present as well (OR = 22.3). These results confirm that the increased risk of deep vein thrombosis in the combined presence of AB alleles and Factor V Leiden is also applicable to the Brazilian population suggesting that ABO blood group typing should be routinely added to FVL in studies involving thrombosis.
Acesso aberto (Open Access)
Prevalence of hereditary risk factors for thrombophilia in Belém, Brazilian Amazon
(2006) YOSHIOKA, France Keiko Nascimento; ARAÚJO, Amélia Goes de; TAVELLA, Marli H.; HAMOY, Igor Guerreiro; GUERREIRO, João Farias
Different risk factors for venous thromboembolism (VTE) have been identified, including hereditary abnormalities in the mechanisms of coagulation and fibrinolysis. We investigated five genetic polymorphisms (FVL G1691A, FII G20210A, MTHFR C677T, TAFI A152G and TAFI T1053C) associated with VTE in individuals from the city of Belém in the Brazilian Amazon who had no history of VTE. No significant difference was found between the observed and expected genotype frequencies for the loci analyzed. We found high frequencies of MTHFR C677T (33.9%) and TAFI T1053C (74%) and low frequencies of FVL (1.6%), FII G20210A (0.8%) and TAFI A152G (0.8%). The FVL G1691A, FII G20210A and MTHFR C677T frequencies were similar to those for European populations and populations of European descent living in the city of Ribeirão Preto in the Brazilian state of São Paulo. The frequency of the two TAFI mutations in the Belém individuals was not significantly different from that described for individuals from Ribeirão Preto. We suggest that the risks for VTE in the population of Belém are of the same magnitude as that observed in European populations and in populations with an expressive European contribution.