Role of prothrombotic polymorphisms in successful or unsuccessful aging

The study of the genetic profile of centenarians aims to identify the genes and allelic variants which may influence a greater life expectancy and that can be considered as predisposing factors associated to the aging diseases, such as Alzheimer. Centenarians, that represent a cohort of selected survivors, show an hypercoagulability state characterised by striking signs of high coagulation enzyme activity, as directly assessed by the tested higher plasma level of some important factors involved in the haemostasis balance. Anyway, these individuals seem to have a reduced susceptibility to dementia, as well as to cardiovascular events. In this study we analyze the frequencies of Leiden Factor V polymorphism (G1691A), and G20210A of prothrombin (FII) in three cohorts of subjects: patients with Alzheimer\u2019s disease (unsuccessful aging), nonagenarians (successful aging) and young healthy controls, to assess whether allelic variants associated to the modification of haemostatic system function, may play a role in the protection or susceptibility to Alzheimer disease, as well as to reach a successful aging. No significant differences were observed in the frequencies of the three groups studied. These results indicate that the presence or absence of the gene variants examined did not influence the achievement of advanced age and are not risk factors for Alzheimer\u2019s disease. The state of hypercoagulability and the possession of these risk alleles appear to be compatible with the achievement of longevity and are not implied as risk factors in Alzheimer disease development

Genetic Background Analysis of Protein C Deficiency Demonstrates a Recurrent Mutation Associated with Venous Thrombosis in Chinese Population

Background: Protein C (PC) is one of the most important physiological inhibitors of coagulation proteases. Hereditary PC deficiency causes a predisposition to venous thrombosis (VT). The genetic characteristics of PC deficiency in the Chinese population remain unknown. Methods: Thirty-four unrelated probands diagnosed with hereditary PC deficiency were investigated. PC activity and antigen levels were measured. Mutation analysis was performed by sequencing the PROC gene. In silico analyses, including PolyPhen-2, SIFT, multiple sequence alignment, splicing prediction, and protein molecular modeling were performed to predict the consequences of each variant identified. One recurrent mutation and its relative risk for thrombosis in relatives were analyzed in 11 families. The recurrent mutation was subsequently detected in a case (VT patients)-control study, and the adjusted odds ratio (OR) for VT risk was calculated by logistic regression analysis. Results: A total of 18 different mutations, including 12 novel variants, were identified. One common mutation, PROC c.565C.T (rs146922325:C.T), was found in 17 of the 34 probands. The family study showed that first-degree relatives bearing this variant had an 8.8-fold (95%CI = 1.1–71.6) increased risk of venous thrombosis. The case-control (1003 vs. 1031) study identified this mutation in 5.88 % patients and in 0.87 % controls, respectively. The mutant allele conferred a high predisposition to venous thrombosis (adjusted OR = 7.34, 95%CI = 3.61–14.94). The plasma PC activity and antigen levels i

Genes influencing coagulation and the risk of aneurysmal subarachnoid hemorrhage, and subsequent complications of secondary cerebral ischemia and rebleeding

We investigated whether genes influencing coagulation are associated with the occurrence of aneurysmal subarachnoid hemorrhage (SAH) and with secondary cerebral ischemia and rebleeding in patients with aneurysmal SAH. Genotyping for factor V Leiden (G1691A), prothrombin G20210A, methylenetetetrahydrofolate reductase (MTHFR) C677T, factor XIII subunit A Val34Leu, Tyr204Phe and Pro564Leu, and factor XIII subunit B His95Arg was performed in 208 patients with aneurysmal SAH and in 925 controls. Secondary cerebral ischemia occurred in 49 (24%) patients and rebleeding in 28 (14%) during their clinical course of 3 months after the aneurysmal SAH. The risk of aneurysmal SAH was assessed as odds ratio (OR) with 95% confidence interval (95% CI). The risk of secondary cerebral ischemia and rebleeding was assessed as hazard ratio (HR) with 95% CI using Cox regression. Carriers of the subunit B His95Arg factor XIII polymorphism had an increased risk of aneurysmal SAH with 23% of the patients homozygous or heterozygous for the variant allele compared to 17% of control subjects (OR 1.5, 95% CI 1.0-2.2). For the remaining genetic variants no effect on the risk of aneurysmal SAH could be demonstrated. A clear relation with the risk of secondary cerebral ischemia and of rebleeding could not be established for any of the genetic variants. We found that aneurysmal SAH patients are more often carriers of the subunit B His95Arg factor XIII polymorphism compared to controls. This suggests that carriers of the subunit B His95Arg factor XIII polymorphism have an increased risk of aneurysmal SAH. Larger studies should confirm our results. As aneurysmal SAH patients who died soon after admission could not be included in the present study, our results only apply to a population of patients who survived the initial hours after the hemorrhage. For the other studied genetic factors involved in coagulation, no association with the occurrence of aneurysmal SAH or with the occurrence of secondary cerebral ischemia or rebleeding after aneurysmal SAH could be demonstrated

The Association of Factor V Leiden and Prothrombin Gene Mutation and Placenta-Mediated Pregnancy Complications: A Systematic Review and Meta-analysis of Prospective Cohort Studies

Marc Rodger and colleagues report the results of their systematic review and meta-analysis of prospective cohort studies that estimated the association of maternal factor V Leiden and prothrombin gene mutation carrier status and placenta-mediated pregnancy complications

The platelet glycoprotein Ia/IIa gene polymorphism C807T/G873A: a novel risk factor for retinal vein occlusion

Retinal vein occlusion (RVO) is associated with hyperhomocysteinaemia and the antiphospholipid syndrome&mdash;disorders known to contribute to both arterial and venous thrombosis. In both of these conditions and RVO, platelet activation occurs. Aspirin, not warfarin, is the most effective antithrombotic agent in RVO and, taken together, these observations suggest an important role for platelets in this common ocular thrombotic condition. Platelet glycoprotein Ia/IIa (GpIa/IIa) is an adhesion molecule mediating platelet&ndash;collagen interactions and is key to the initiation of thrombosis. Recently, the cellular density of this molecule was shown to be determined by two silent, linked polymorphisms (C807T/G873A) within the GpIa/IIa gene. There is evidence that some of the resulting genotypes are associated with thrombo-embolic disease. This study therefore aimed to establish the prevalence of the GpIa/IIa polymorphisms and the three commonest hereditary thrombophilic disorders (prothrombin gene G20210A (PT) mutation, Factor V Leiden (FVL), and the thermolabile methylene tetrahydrofolate reductase C677T (MTHFR) mutation) in patients with RVO and normal controls. The GpIa/IIa polymorphisms and thrombophilic abnormalities were all identified using the polymerase chain reaction.Our results show that the frequency of the GpIa/IIa polymorphisms was similar in our normal control population to previously published series. Patients with RVO, however, had only a 10% (4/40) frequency of the lowest risk subtype (CC/GG) compared to 37.5% (15/40) in the control group&mdash;P 0.0039. The incidence of the PT, FVL, and MTHFR thrombophilic mutations was not different between the two groups, but interestingly none of the 7/40 RVO cases with a PT, FVL, or MTHFR mutation had the low-risk GpIa/IIa genotype while all but one of the controls did&mdash;P&lt;0.05. Thus, 17.5% of RVO patients harboured more than one prothrombotic abnormality. The principal difference between the RVO and control group was the very high incidence of the intermediate-risk GpIa/IIa subtype (CT/GA)&mdash;82.5 vs 50%, P&lt;0.05.These results suggest a major role for GpIa/IIa polymorphisms in the pathogenesis of RVO.<br /