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Although the role of environmental factors in the development of acute myocardial infarction (AMI) has been clearly established, the role of genetic factors is still undefined. The aim of this study was to investigate the association between various gene polymorphisms in the haemostatic system and the risk of myocardial infarction in a very genetic restricted area population of Sardinian young adults with AMI. The study case-control involved 71 patients who had survived a first MI at a mean age of 47,2 years and 150 healthy subjects. No differences in the allele or genotype frequencies were seen between the study groups for the fibrinogen, prothrombin, factor V, factor VII, vWF, TM, PAI-1, TPO gene, and PLA and HPA-2 genes polymorphisms. Indeed differences statistically significant were detected for A5709G in the TPO gene (P= 0,041), and I/D dimorphism in the eNOS gene (P= 0,016). We therefore conclude that among all the investigated polymorphisms only the 5709G and eNOS4a alleles seem to confer protection against MI in the young age of Sardinian people.

Background: Defects of integrin alpha(IIb)beta(3) are typical of Glanzmann's thrombasthenia, an inherited autosomal recessive bleeding disorder characterized by the failure of platelets to aggregate in response to all physiological agonists, but with no abnormalities in the number or size of platelets. Although large heterogeneity has been described for Glanzmann's thrombasthenia, no family has so far been described as having an autosomal dominant form of this disease., Design and Methods: We describe two Italian families with moderate thrombocytopenia with large platelets, defective platelet function and moderate/severe mucocutaneous bleeding, transmitted as an autosomal dominant trait and associated with a novel integrin beta(3)-gene (ITGB3) mutation., Results: The characteristics of our families are moderate macrothrombocytopenia and defective platelet function associated with a mild reduction of surface alpha(Ib) beta(3), impaired platelet aggregation to physiological agonists but not to ristocetin, normal clot retraction, reduced fibrinogen binding and expression of activated alpha(IIb)beta(3) upon stimulation, normal platelet adhesion to immobilized fibrinogen but reduced platelet spreading and tyrosine phosphorylation, indicating defective alpha(IIb)beta(3)-mediated outside-in signaling. Molecular analysis revealed a novel mutation of ITGB3 that determines an in-frame deletion producing the loss of amino acids 647-686 of the betaTD ectodomain of integrin beta(3). Haplotype analysis indicated that the two families inherited the mutation from a common ancestral chromosome., Conclusions: This novel autosomal dominant macrothrombocytopenia associated with platelet dysfunction raises interesting questions about the role of integrin beta(3), and its betaTD domain, in platelet formation and function.

In the present study, we have analyzed four highly polymorphic regions (STRs) chosen from four candidate genes involved in: (1) Platelet aggregation: alpha subunit of the platelet GpIIb/GpIIIa integrin complex (GpIIIa (CT)n; 17q21.31), (2) Coagulation fibrinolysis: Plasminogen Activator Tissue (PLAT5 (TG)14(TA)12; 8p12-q11.2) and Plasminogen Activator Inhibitor-1 (PAI-1 (CA)n; 7q21.3-q22), (3) Oxidative metabolism: the inducible nitric oxide (NO) synthase (iNOS) gene (NOS2A (CCTTT)n; 17cen-q11.2). Allele frequencies for these four STR loci were investigated in several Mediterranean populations. The population data deviate from the Hardy-Weinberg equilibrium in all populations for GpIIIa (CT)n polymorphism.

Objective: The platelet GPIIIa plays a pivotal role in platelet aggregation. Previous studies showed an association between the GPIIIa Pl(A1/A2) polymorphism and coronary thrombosis, while there is only contrasting evidence about its role in stroke. We explored the possibility that this polymorphism represents a risk factor for stroke in hypertensive patients., Methods: We studied two populations. In loco, we genotyped 140 hypertensive control individuals and 28 hypertensive patients with ischemic stroke. Furthermore, we performed an analysis of previously published data of 451 Sardinian hypertensive patients, already characterized and genotyped., Results: Association analysis revealed that the Pl(A2) distribution was similar between hypertensive patients with and without stroke, but when considering a more homogeneous population of high-risk hypertensive patients, defined according to ESH/ESC 2003 guidelines, we observed that the frequency of the Pl(A2) allele was higher among stroke versus nonstroke patients (stroke, 46.4%; nonstroke, 22.6%; P = 0.01). The multiple regression analysis taking into account this polymorphism among other factors known to contribute to ischemic stroke confirmed the Pl(A2) allele as an additive risk factor for stroke (B = 0.986, Wald = 4.943, P < 0.03), increasing the risk of stroke by 2.9 (95% confidence interval = 1.23-6.85, P < 0.02). Similar results were obtained in the Sardinian population: in hypertensive patients with three or more risk factors, Pl(A2) increases the risk (odds ratio = 2.8, 95% confidence interval = 1.3-6.0, P < 0.001) and is an additive risk factor for stroke (B = 1.073, Wald = 6.920, P < 0.01)., Conclusions: Our data suggest that the Pl(A2) polymorphism is a genetic determinant of ischemic stroke in a selected high-risk hypertensive population.

Glanzmann's thrombasthenia (GT) is a genetically heterogeneous autosomal recessive syndrome associated with a bleeding tendency. To elucidate molecular basis of GT we have screened for mutations 30 GT patients. On the whole, 21 different candidate causal mutations, 17 in the alphaIIb and 4 in the beta3 gene have been found. Only two (alphaIIb Pro145Ala and IVS3(-3)-418del) have been previously reported. Nine mutations (42.9%) were likely to produce truncated proteins, whereas the remaining 12 were missense mutations that affected highly conserved residues in alphaIIb and beta3 genes. Six mutations were found in different patients suggesting a possible founder effect. The wide spectrum of expressivity, ranging from mild to severe also among patients carrying the same mutations, provided evidence for a role of different loci or circumstantial factors. In conclusion, we have identified a spectrum of unreported mutations that may be of value to unravel the role of specific regions of alphaIIb and beta3 genes.