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Glanzmann thrombasthenia (GT) is a rare autosomal recessive bleeding disorder characterized by impaired platelet aggregation due to defects in integrin αIIbβ3, a fibrinogen receptor. Platelet phenotypes and allelic variations in 28 Turkish GT patients are reported. Platelets αIIbβ3 expression was evaluated by flow cytometry. Sequence analyzes of ITGA2B and ITGB3 genes allowed identifying nine variants. Non-sense variation effect on αIIbβ3 expression was studied by using transfected cell lines. 3D molecular dynamics (MDs) simulations allowed characterizing structural alterations. Five new alleles were described. αIIb:p.Gly423Asp, p.Asp560Ala and p.Tyr784Cys substitutions impaired αIIbβ3 expression. The αIIb:p.Gly128Val substitution allowed normal expression; however, the corresponding NM_000419.3:c.476G>T variation would create a cryptic donor splicing site altering mRNA processing. The β3:p.Gly540Asp substitution allowed αIIbβ3 expression in HEK-293 cells but induced its constitutive activation likely by impairing αIIb and β3 legs interaction. The substitution alters the β3 I-EGF-3 domain flexibility as shown by MDs simulations. GT variations are mostly unique although the NM_000419.3:c.1752 + 2 T > C and NM_000212.2:c.1697 G > A variations identified in 4 and 8 families, respectively, might be a current cause of GT in Turkey. MD simulations suggested how some subtle structural variations in the β3 I-EGF domains might induce constitutive activation of αIIbβ3 without altering the global domain structure.

Objective: The aim of this study was to investigate the association between the genetic heterogeneity of platelet glycoproteins Ia (GpIa-C807T) and IIIa (GpIIIa-PlA1/PlA2) and spontaneous abortions., Study Design: Two hundred and twenty two women with a history of unexplained spontaneous miscarriages and no successful pregnancy, and 60 fertile women serving as controls were genotyped for the GpIa-C807T and GpIIIa-PlA1/PlA2 polymorphisms by pyrosequencing., Results: In comparison with the common alleles homozygotes, GpIa-807T and GpIIIa-PlA2 carriers had an increased risk of fetal loss (OR = 3.36, 95%CI: 1.85-6.11, p < 0.001, and OR = 2.58, 95%CI: 1.30-5.13, p = 0.006, respectively). For subjects who were combined carriers of the GpIa-807T and GpIIIa-PlA2 alleles, the risk increased further (OR = 9.13, 95%CI: 2.99-27.82, p < 0.001). The above ORs were highest for women who were younger than 30 years of age., Conclusions: The GpIa-C807T and GpIIIa-PlA1/PlA2 polymorphisms and more pronouncedly their combination are associated with increased risk of spontaneous abortions. The correlations were stronger for younger patients. Our results indicate that GpIa-807T and GpIIIa-PlA2 are susceptibility alleles for fetal loss in the Greek population.

The aim of the study was to investigate the combined impact of the genetic heterogeneity of the glycoproteins Ia (GpIa) and IIIa (GpIIIa) and the platelet-endothelial cell adhesion molecule-1 (PECAM-1) and P-Selectin genes on IVF embryo transfer implantation failures (IVF-ET failures). Sixty nulligravida women with previous IVF-ET failures and 60 fertile controls were genotyped for the GpIa-C807T, GpIIIa-PlA1/PA2, PECAM-1-C373G (Leu125Val) and P-Selectin-A37674C (Thr715Pro) polymorphisms by pyrosequencing. Compared with wild-type combined homozygotes, carriers of combinations of risk alleles in two gene loci were at significantly increased risk for IVF-ET failure, whereas carriers of the combination of GpIa-807T, GpIIIa-PlA2 and PECAM-1-373G alleles had OR = 52.50 (95%CI: 4.05-680.95, p < .001). The area under the receiver-operating characteristic curve (AUC) based on the number of polymorphisms and the number of risk alleles per subject was 75.4% (95%CI: 66.7%-82.8%, p < .001) and 72.5% (95%CI: 63.6%-80.3%, p < .001), respectively. The OR per polymorphism and risk allele increase was 4.26 (95%CI: 2.15-8.41, p < .001) and 2.85 (95%CI: 1.71-4.76, p < .001), respectively. The above associations were more robust among younger women. The combined analysis of these polymorphisms revealed strong association of combined carriers with IVF-ET failures especially for younger women and provided a genetic risk score with good diagnostic accuracy in the prediction of IVF-ET failures.

Platelet glycoprotein (GP) mediated the role of platelet in coagulation. Platelet GP Ia 807C/T is the only GP polymorphism associated with the expression levels of GP Ia/IIa (the platelet collagen receptor). Recently, the GP Ia 807C/T polymorphism has been reported to have no association with cerebral hemorrhage (CH) in two studies pertained to Caucasian populations. The purpose of this study is to evaluate the association between platelet GP Ia 807C/T polymorphism and CH in a Han Chinese population. We performed genotype analysis for platelet GP Ia 807C/T polymorphism in a case-control study involving 195 patients with CH and 116 age- and sex-matched controls. In contrast to previous reports, we found that the frequencies of GP Ia 807C/T T allele, CT and TT genotype were much higher in CH patients than in controls (33.9% vs. 22.8%, p = 0.004; 45.5% and 11.1% vs. 40.4% and 2.6%, p = 0.022). Logistic regression analysis revealed that the presence of GP Ia 807C/T C allele and CC genotype were both associated with a decreased risk of CH compared with T allele, CT and TT genotypes, respectively (adjusted odds ratio [OR] = 0.565, 95% CI: 0.384-0.887, p = 0.005; adjusted OR = 0.172, 95% CI: 0.043-0.639, p = 0.009; adjusted OR = 0.254, 95% CI: 0.085-0.961, p = 0.041, respectively). These findings indicated that platelet GP Ia 807C/T polymorphism could be a protective factor of CH in the Chinese population.

Polymorphisms in platelet receptor genes may influence platelet function. This study aimed to assess the impact of five polymorphisms of genes encoding platelet receptors on the risk of ischemic and bleeding events in ST-elevation myocardial infarction (STEMI) patients after percutaneous coronary intervention (PCI). 503 consecutive Chinese patients with STEMI after an uneventful PCI and exposed to standard dual antiplatelet therapy for 12 months were enrolled. Polymorphisms of platelet receptors, GPIa (ITGA2, 807C > T, rs1126643), GPVI (GP6, 13254T > C, rs1613662), PAR-1 (F2R, IVS-14A > T, rs168753) and P2Y12 (P2RY12, 34C > T, rs6785930 and H1/H2 haplotype, 52G > T, rs6809699) were detected by the ligase detection reaction. The follow-up period was 12 months. Overall, 34 (6.8%) ischemic events occurred and 46 (9.1%) major bleedings occurred. Multivariate Cox regression analysis showed the carriage of F2R rs168753 minor allele was an independent predictor of the composite ischemic events (HR 0.387, 95% CI 0.193-0.778, p = 0.008) after adjusted for established risk factors. Multivariate logistic regression model identified that carriage of P2RY12 rs6809699 minor allele (OR 2.71, 95% CI 1.298-5.659, p = 0.008) was an independent predictor of major bleedings. The associations were then validated in a second cohort of 483 STEMI patients. In STEMI patients after PCI, F2R rs168753 minor allele could significantly contribute to the risk of ischemic events, and P2RY12 rs6809699 minor allele could predict bleedings. The genetic testing of platelet receptors can be valuable in predicting adverse events in STEMI patients after PCI.

Previous studies have implicated that the Ig-ITIM superfamily member, CEACAM1 may regulate integrin function. While CEACAM1 has been demonstrated to play a role as an inhibitory co-receptor of ITAM-associated GPVI/FcR γ-chain signaling pathways in platelets, its physiologic role in integrin αIIbβ3-mediated platelet function is unclear. In this study, we investigate the functional importance of Ceacam1 in murine platelets. We show that CEACAM1 is constitutively associated with integrin αIIbβ3 in resting human and mouse platelets as demonstrated by co-immunoprecipitation studies. Using Ceacam1-deficient mice, we show that they have prolonged tail bleeding times and volume of blood lost that is corrected by reconstitution with platelet Ceacam1. Ceacam1(-/-) platelets have moderate integrin αIIbβ3 mediated functional defects with impaired kinetics of platelet spreading on fibrinogen and failure to retract fibrin clots in vitro. This functional integrin αIIbβ3 defect could not be attributed to altered integrin αIIbβ3 expression. Ceacam1(-/-) platelets displayed normal "inside-out" signaling properties as demonstrated by normal agonist-induced binding of soluble (fluorescein isothiocyanate) FITC-fibrinogen, JON/A antibody binding, and increases in cytosolic free calcium levels. This study provides direct evidence that Ceacam1 is essential for normal integrin αIIbβ3-mediated platelet function and that disruption of mouse Ceacam1 induced moderate integrin αIIbβ3-mediated functional defects.

Thrombophilic genetic factors have been shown to play an important role in implantation outcome after in vitro fertilisation (IVF). In this pilot study we investigated the frequencies of glycoprotein Ia (GpIa)-C807T and GpIIIa-PlA1/PlA2 polymorphisms in 60 nulligravidae women with a history of unexplained IVF implantation failures and compared them with 60 healthy fertile women. We found statistically significant associations between the GpIa-C807T and GpIIIa-PlA1/PlA2 polymorphisms and IVF implantation failure (odds ratio [OR] = 3.45, 95% confidence interval [CI]: 1.63-7.30, p = 0.001; and OR = 2.86, 95% CI: 1.27-6.45, p = 0.010, respectively) with the risk being higher for combined carriers of GpIa-807T and GpIIIa-PlA2 alleles (OR = 10.13, 95% CI: 2.85-35.99, p < 0.001), suggesting a synergistic effect of the two polymorphisms. The above associations were strongest for the youngest age group. Our results indicate that GpIa-807T and GpIIIa-PlA2 may be susceptibility alleles for IVF implantation failure.

Background: The role of genetic variants in the pathogenesis of stroke has not been fully elucidated. Several studies have been examined the association of the Integrin alpha2 (ITGA2) gene-C807T (rs1126643) polymorphism with ischemic stroke susceptibility. However, the results of these studies are inconsistent. In order to explore this association more deeply, we performed a meta-analysis., Methods: We collected case-control studies concerning the relationship between the C807T polymorphism and ischemic stroke, and odd ratios (OR) with corresponding 95% confidence intervals (CI) were used to describe the relationships. Inconsistency index (I(2)) and Cochran's Q statistic were used to check heterogeneity. Publication bias was tested by funnel plots and Egger's test., Results: Fifteen studies with 2242 cases and 2408 controls were included. Our meta-analysis results indicated an association between the C807T polymorphism and the risk of ischemic stroke in the overall population, Asians and the subgroup of hospital-based people. However, statistically association was not observed for Caucasians and non-hospitalized individuals., Conclusions: The ITGA2 gene C807T polymorphism may be a susceptible predictor of the risk of ischemic stroke. More data are needed to elucidate the relationship further.

This study of infertile women prior in vitro fertilization (IVF) is focused at the genetic and acquired thrombophilia before the IVF program, the identification of the frequency of occurrence of thrombophilia in them, the impact of thrombophilia of the offensive, the course and outcome of pregnancies, to improve the quality of cycles in terms of a pregnancy and childbirth. Forty-five women with infertility were examined. Thirty-two (71%) were identified thrombophilia: genetic thrombophilia in 32 cases (100%), among them a combination of several forms of genetic thrombophilia - 21 (63%) of them, other forms of thrombophilia (genetic and acquired) - in 5 of them (16%). In IVF 23 (72%) women became pregnant. In 87% of pregnancies ended in spontaneous birth, in 13% of cases of preterm birth.

The question as to whether Glanzmann thrombasthenia patients with ITGB3 defects and deficiencies of both αIIbβ3 and αvβ3 show phenotypic differences to those with abnormalities exclusive to αIIbβ3 is unresolved. Studies on β3-deficient mice have shown an increased bone mass. Here we review the literature on bone defects in thrombasthenia patients and report the molecular analysis of a patient associating a lifelong thrombasthenia-like syndrome with skeletal defects. We show that the patient is compound heterozygote for Arg327His and Gly391Arg mutations in αIIb, with one mutation inherited from each parent. Modelling strongly suggested that both mutations act by destabilizing the αIIb beta propeller. So it appears likely that this patient has a combination of co-expressed genetic defects.

Immune thrombocytopenic purpura (ITP) is an autoimmune disease characterized by the presence of autoantibodies developing against thrombocyte membrane glycoproteins (GPs), such as GPIIa/IIIa and GPIb/IX. Single nucleotide polymorphisms (SNPs) of inflammatory cytokine genes were investigated in 71 patients with chronic ITP and 71 healthy controls, and they were compared with the clinical parameters. The polymorphisms in the SNPs were investigated with the polymerase chain reaction, polymerase chain reaction with sequence specific primer, and polymerase chain reaction-restriction fragment length polymorphism methods. It was found that the high expression of TNF-alpha (-308) AG phenotype significantly increased in cases with ITP (odds ratio, OR: 0.318, 95% confidence intervals, CI: 0.103-0.987, p < 0.05). TT genotype in TGF-beta 1 (codon 10) significantly decreased in ITP in comparison with the controls (OR: 0.342, 95% CI: 0.149-0.787, p = 0.016). IFN-gamma (+874) TT genotype was detected to be high in cases with ITP (OR: 3.301, 95% CI: 1.400-7.784, p < 0.05), whereas AA genotype was found to be significantly lower (OR: 4.993, 95% CI: 1.586-15.721, p < 0.05). MBL (codon 54) BB genotype (OR: 1.164, 95% CI: 1.059-1.279, p < 0.05) and IL1A A1/A2 genotype (OR: 0.249, 95% CI: 0.076-0.815, p < 0.05) were found to be significantly higher in cases with ITP than in healthy controls. TNF-alpha (-308) AG phenotype was detected to be significantly higher in steroid-refractory and splenectomized cases at the end of the first year than in the steroid-responsive (complete response (CR) and remission (R)) cases (OR: 4.137, 95% CI: 1.156-14.807, p < 0.05). When we compared the cases, from whom we obtained a CR at their first steroid response, with 12 cases, who entered R but from whom we could not obtain any CR, the frequencies of IFN-gamma (+874) AA genotype were found as 12 (20.3%) and 6 (50%) (OR: 0.082, 95% CI: 0.009-0.793, p < 0.05). MBL (codon 54) AB genotype was detected to be significantly higher in CR patients than in R cases (OR: 1.273, 95% CI: 1.110-1.459, p < 0.05). With these findings, it was found that TNF-alpha/AG, TGF-beta 1/TT, IFN-gamma/TT, MBL/BB, and IL-1RA A1/A2 genotypes were detected as the genes of susceptibility to ITP, while TNF-alpha/AG, IFN-gamma/AA, and MBL/AB genotypes might be important in response to steroid treatment.

Unlabelled: There are limited data on the influence of genetic polymorphisms in atrial fibrillation (AF) stroke risk. We hypothesized that a functional haemostatic polymorphism, that is, the factor VII -323 Del/Ins polymorphism, would influence the prothrombotic state associated with AF, as well as stroke risk. Other functional polymorphisms were also tested., Methods: We performed a cross-sectional study of 119 AF patients, who were compared to 96 patients with stroke secondary to AF. In the first patient group, we analysed plasma prothrombin fragment 1+2 levels (F1+2, an index of thrombin generation) to reflect the prothrombotic state of AF., Results: AF patients carrying the -323 Ins allele had lower plasma F1+2 levels (P=0.015). After multivariate analysis adjusted by age, sex and clinical risk factors, advanced age and 807C/T polymorphism of glycoprotein Ia (GPIa) gene were associated with higher risk of ischaemic stroke (OR: 1.06; P=0.003 and OR: 1.91; P=0.025), whilst FVII Ins -323 allele was associated with lower stroke risk (OR: 0.41; P=0.017)., Conclusion: FVII -323 Ins allele may modulate the prothrombotic state associated with AF. Despite the small sample size, we found that FVII Ins -323 allele could be associated with a lower stroke risk in AF, whereas the 807C/T polymorphism may increase the risk.