Navegando por Assunto "Trombose venosa"

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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)
Heterogeneous ethnic distribution of the factor V leiden mutation
(1999-06) FRANCO, Rendrik França; ELION, Jacques; SANTOS, Sidney Emanuel Batista dos; ARAÚJO, Amélia Goes de; TAVELLA, Marli H.; ZAGO, Marco Antonio
Inherited resistance to activated protein C caused by the factor V Leiden (FVL) mutation is the most common genetic cause of venous thrombosis yet described, being found in 20-60% of patients with venous thrombophilia. A relationship between the FVL mutation and an increased predisposition to arterial thrombosis in young women was recently reported. We assessed the prevalence of the FVL mutation in 440 individuals (880 chromosomes) belonging to four different ethnic groups: Caucasians, African Blacks, Asians and Amerindians. PCR amplification followed by MnlI digestion was employed to define the genotype. The FVL mutation was found in a heterozygous state in four out of 152 Whites (2.6%), one out of 151 Amerindians (0.6%), and was absent among 97 African Blacks and 40 Asians. Our results confirm that FVL has a heterogeneous distribution in different human populations, a fact that may contribute to geographic and ethnic differences in the prevalence of thrombotic diseases. In addition, these data may be helpful in decisions regarding the usefulness of screening for the FVL mutation in subjects at risk for thrombosis.
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.