Blindness among nursing home residents

Prothrombotic gene polymorphisms and atherothrombotic cerebral infarction

OBJECTIVES

To test the hypothesis whether risk genotypes of the prothrombotic gene polymorphisms (I/D 4G5G PAI-1, G1691A factor V point mutation, factor VII Arg/Gln353) are risk factors for ACI in the Slovene population. The study sought an association between the insertion/deletion 4G/5G-plasminogen activator inhibitor 1 (PAI-1) gene polymorphism, the 1691G-A factor V point mutation or the arg353-to-gln factor VII gene polymorphism and atherothrombotic cerebral infarction (ACI).

MATERIAL AND METHODS

Ninety-six Slovene patients who suffered ACI were compared with 115 control subjects clinically free of cerebrovascular disease. Insertion/deletion 4G/5G PAI-1 gene polymorphism, 1691G-A factor V point mutation and arg353-to-gln polymorphism in the factor VII were determined using polymerase chain reaction.

RESULTS

The 4G4G genotype of 4G5G PAI-1 gene polymorphism was less frequent in cases (21.9%) than in controls (35.6%; OR = 0.5, 95% CI = 0.3-1; P = 0.033). No association was found either between the factor V point mutation (1691G-A) or the RR genotype of the factor VII Arg/Gln353 gene polymorphism and the risk of ACI using univariate analysis.

CONCLUSION

The 4G/4G-PAI-1 genotype might be a protective factor against ACI, whereas the factor V point mutation (1691G-A) and the factor VII Arg/Gln353 gene polymorphism have not proved to be risk factors for ACI.

Clinical significance of gene-diagnosis for defects in coagulation factors and inhibitors

cDNA sequences of all known coagulation factors and inhibitors of coagulation have been described and an enormous number of disease generating mutations in these factors has been found by genetic analysis of affected families. The vast majority of these defects have severe clinical consequences such as spontaneous bleeding or predisposition to venous thrombosis and pulmonary embolism. While all the genetic defects described so far cause disease, or at least represent a risk factor for diseases such as bleeding or thrombosis, only a minority of these conditions actually need DNA analysis to be detected and/or treated properly. The purpose of this review is therefore to describe clinical situations in which the knowledge of the underlying genetic defect is important for decision making in patients with inherited hemophilia or thrombophilia.

Factor V Leiden: The Copenhagen City Heart Study and 2 meta-analyses

Factor V Leiden (FVL) is associated with venous thrombosis; however, an association between FVL and arterial thrombosis remains controversial. We investigated FVL as a risk factor for myocardial infarction (MI), ischemic stroke (IS), or non-MI ischemic heart disease (non-MI-IHD). The design was 3 case-control studies and 3 prospective studies with 21 years' follow-up. The setting was the general population in Copenhagen, Denmark. The participants for The Copenhagen City Heart Study were 20- to 95-year-old participants without cardiovascular disease (control population, n = 7907) or participants diagnosed with MI (n = 469), IS (n = 231), or non-MI-IHD (n = 365). In addition, 3 independent patient populations from Copenhagen University Hospital with MI (n = 493), IS (n = 231), or non-MI-IHD (n = 448) were included. We measured FVL genotype; major cardiovascular risk factors; and MI, IS, and non-MI-IHD incidence and prevalence. Prevalences of FVL heterozygotes and homozygotes in control subjects from the general population were 7.7% and 0.2%. Odds ratios and relative risks of MI in FVL carriers (heterozygotes + homozygotes) versus noncarriers were 1.24 (95% confidence interval [CI], 0.91-1.69) and 0.83 (0.58-1.20) in case-control and prospective studies, respectively. Corresponding risks for IS were 0.92 (95% CI, 0.56-1.53) and 0.68 (0.45-1.04), and for non-MI-IHD 1.01 (95% CI, 0.71-1.44) and 0.97 (0.66-1.42). Findings from The Copenhagen City Heart Study suggest that FVL is not associated with MI, IS, or non-MI-IHD.

Resistance to activated protein C: role in venous and arterial thrombosis

Activated protein C resistance is the most prevalent cause of thrombophilia: it is found in 20 to 30% of patients with a deep venous thrombosis history. Activated protein C resistance is due to an arginine 506 to glutamine mutation in factor V. This mutation prevents normal inactivation of activated factor V by activated protein C. The estimated increase in relative risk of venous thrombosis is 5- to 10-fold in heterozygotes, and 50- to 100-fold in homozygotes. Activated protein C resistance does not seem to play a role in arterial thrombosis and in the occurrence of myocardial infarction.