Testing for lipoprotein(a) concentration and apolipoprotein(a) phenotypes: method standardization and pediatric reference values.

Increased levels of lipoprotein(a) (Lp[a])are known independent risk factor for atherosclerosis, heart disease, and stroke in adults. Even in children it could be shown that elevated levels of Lp(a) are an independent risk factor for symptomatic thromboembolism. The aim of this work was to describe the methods used for evaluating Lp(a) phenotypes, to link them to Lp(a) plasma concentrations, and to establish age-dependent reference values in children.

Fibrinogen alpha and gamma genes and factor VLeiden in children with thromboembolism: results from 2 family-based association studies.

Previous case-control studies showed that genetic variation in the fibrinogen gamma gene (FGG) increased the risk for deep vein thrombosis (VT) in adults. We investigated the association between the fibrinogen alpha (FGA) and FGG haplotypes, the factor V(Leiden)-mutation, and pediatric VT and thromboembolic stroke (TS) in 2 independent study samples. Association analysis revealed that the FGA-H1 and FGG-H2 haplotypes were significantly overtransmitted to VT patients (FGA-H1, P = .

Association of the protein Z ATG haplotype with symptomatic nonvascular stroke or thromboembolism in white children: a family-based cohort study.

To clarify the role of protein Z (PZ) in children with stroke/thromboembolism (TE), the present haplotype (HT)-based family study was performed. We genotyped 365 pediatric stroke/TE families (stroke n = 216; TE n = 149) for 4 single nucleotide polymorphisms (SNPs; rs3024718, rs3024731, rs3024772, and rs3024778) to assess the association between genetic variation within a conserved block of linkage disequilibrium harboring the PZ gene and pediatric TE. Association was assessed with use of the transmission disequilibrium test (TDT), corrected for multiple testing (permutation testing: HAPLOVIEW).

Genetics of hemostasis: differential effects of heritability and household components influencing lipid concentrations and clotting factor levels in 282 pediatric stroke families.

Background: The identification of heritable and environmental factors possibly influencing a condition at risk should be a prerequisite for the search for the proportion of variance attributable for shared environmental effects (c(2)) modulating the risk of disease. Such epidemiologic approaches in families with a first acute ischemic stroke during early childhood are lacking.

Objectives: Our goal was to estimate the phenotypic variation within lipid concentrations and coagulation factor levels and to estimate the proportions attributable to heritability (h(2)r) and c(2) in pediatric stroke families.

Elevated alpha1-antitrypsin is a risk factor for arterial ischemic stroke in childhood.

Alpha1-antitrypsin (alpha1-AT) is a physiological inhibitor of activated protein C (APC) and therefore decreased APC activity. APC itself causes an anticoagulant effect by inactivating factors Va and VIIIa. The present case-control study was performed to evaluate the role of the elevated alpha1-AT concentration in pediatric patients with ischemic stroke (IS).

Total tissue factor pathway inhibitor is an independent risk factor for symptomatic paediatric venous thromboembolism and stroke.

Tissue factor pathway inhibitor (TFPI) plays an important role in inhibiting tissue factor-induced coagulation by a factor Xadependent pathway of the activated tissue-factor VIIa complex. Decreased values of the latter inhibitor have been recently reported in adult patients with venous thrombosis (VT) or ischaemic stroke (IS). The present case-control study was therefore performed to evaluate whether a decreased TFPI concentration is also involved in paediatric symptomatic thromboembolism (ST).