ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
Collection
Years
  • 1
    Publication Date: 1999-11-01
    Description: With the aim of establishing whether the HR2 haplotype in factor V affects the risk of venous thromboembolism, a retrospective multicenter cohort study was performed in 810 family members identified through 174 probands who suffered from at least 1 episode of deep vein thrombosis and/or pulmonary embolism and had an inherited defect associated with thrombophilia (antithrombin, protein C, or protein S deficiency; factor V R506Q or prothrombin G20210A). Fifty-eight percent (468/810) of the family members had an inherited defect and 10% (47/468) were symptomatic. The HR2 haplotype was found in association with factor V R506Q more frequently in family members with venous thromboembolism (18%) than in those without (8%). Double heterozygosity for factor V R506Q and HR2 conferred a 3- to 4-fold increase in the relative risk of venous thromboembolism compared with factor V R506Q alone. The median age at first event was lower when the 2 defects were associated (46v 52 years). No increase in risk of venous thromboembolism could be demonstrated when the HR2 haplotype was associated with inherited thrombophilic defects other than factor V R506Q. Because both factor V R506Q and the HR2 haplotype are very frequent, the effect of their coinheritance on the risk of venous thromboembolism might represent a clinically relevant issue, and screening for HR2 in carriers of factor V R506Q should be considered.
    Print ISSN: 0006-4971
    Electronic ISSN: 1528-0020
    Topics: Biology , Medicine
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 1999-11-01
    Description: With the aim of establishing whether the HR2 haplotype in factor V affects the risk of venous thromboembolism, a retrospective multicenter cohort study was performed in 810 family members identified through 174 probands who suffered from at least 1 episode of deep vein thrombosis and/or pulmonary embolism and had an inherited defect associated with thrombophilia (antithrombin, protein C, or protein S deficiency; factor V R506Q or prothrombin G20210A). Fifty-eight percent (468/810) of the family members had an inherited defect and 10% (47/468) were symptomatic. The HR2 haplotype was found in association with factor V R506Q more frequently in family members with venous thromboembolism (18%) than in those without (8%). Double heterozygosity for factor V R506Q and HR2 conferred a 3- to 4-fold increase in the relative risk of venous thromboembolism compared with factor V R506Q alone. The median age at first event was lower when the 2 defects were associated (46v 52 years). No increase in risk of venous thromboembolism could be demonstrated when the HR2 haplotype was associated with inherited thrombophilic defects other than factor V R506Q. Because both factor V R506Q and the HR2 haplotype are very frequent, the effect of their coinheritance on the risk of venous thromboembolism might represent a clinically relevant issue, and screening for HR2 in carriers of factor V R506Q should be considered.
    Print ISSN: 0006-4971
    Electronic ISSN: 1528-0020
    Topics: Biology , Medicine
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 1997-08-15
    Description: Factor V gene polymorphisms were investigated to detect components that may contribute to the activated protein C (APC) resistance phenotype in patients with venous thromboembolism. A specific factor V gene haplotype (HR2) was defined by six polymorphisms and its frequency was found to be similar in normal subjects coming from Italy (0.08), India (0.1), and Somalia (0.08), indicating that it was originated by ancestral mutational events. The relationship between the distribution of normalized APC ratios obtained with the functional assay and haplotype frequency was analyzed in patients heterozygous for factor V R506Q (factor V Leiden). The HR2 haplotype was significantly more frequent in patients with ratios below the 15th percentile than in those with higher ratios or in normal controls. Moreover, the study of 10 patients with APC resistance in the absence of the factor V R506Q mutation showed a 50-fold higher frequency of HR2 homozygotes. The HR2 haplotype was associated with significantly lower APC ratios both in patients with venous thromboembolism and in age- and sex-matched controls. However, the two groups showed similar HR2 haplotype frequencies. Plasma mixing experiments showed that an artificially created double heterozygote for the factor V R506Q mutation and the HR2 haplotype had an APC ratio lower than that expected for a simple R506Q heterozygote. Time-course experiments evaluating the decay of factor V in plasma showed the normal stability of the molecule encoded by the factor V gene marked by the HR2 haplotype, which ruled out the presence of a pseudo-homozygous APC resistance mechanism. Our results provide new insights into the presence of factor V genetic components other than the factor V R506Q that are able to contribute to the APC resistance phenotype in patients with venous thromboembolism.
    Print ISSN: 0006-4971
    Electronic ISSN: 1528-0020
    Topics: Biology , Medicine
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 1997-08-15
    Description: Factor V gene polymorphisms were investigated to detect components that may contribute to the activated protein C (APC) resistance phenotype in patients with venous thromboembolism. A specific factor V gene haplotype (HR2) was defined by six polymorphisms and its frequency was found to be similar in normal subjects coming from Italy (0.08), India (0.1), and Somalia (0.08), indicating that it was originated by ancestral mutational events. The relationship between the distribution of normalized APC ratios obtained with the functional assay and haplotype frequency was analyzed in patients heterozygous for factor V R506Q (factor V Leiden). The HR2 haplotype was significantly more frequent in patients with ratios below the 15th percentile than in those with higher ratios or in normal controls. Moreover, the study of 10 patients with APC resistance in the absence of the factor V R506Q mutation showed a 50-fold higher frequency of HR2 homozygotes. The HR2 haplotype was associated with significantly lower APC ratios both in patients with venous thromboembolism and in age- and sex-matched controls. However, the two groups showed similar HR2 haplotype frequencies. Plasma mixing experiments showed that an artificially created double heterozygote for the factor V R506Q mutation and the HR2 haplotype had an APC ratio lower than that expected for a simple R506Q heterozygote. Time-course experiments evaluating the decay of factor V in plasma showed the normal stability of the molecule encoded by the factor V gene marked by the HR2 haplotype, which ruled out the presence of a pseudo-homozygous APC resistance mechanism. Our results provide new insights into the presence of factor V genetic components other than the factor V R506Q that are able to contribute to the APC resistance phenotype in patients with venous thromboembolism.
    Print ISSN: 0006-4971
    Electronic ISSN: 1528-0020
    Topics: Biology , Medicine
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...