Inherited prothrombotic risk factors in children with stroke, transient ischemic attack, or migraine.

OBJECTIVE: The aim of this study was to investigate the prevalence and possible association of inherited prothrombotic risk factors in children with stroke, transient ischemic attack, or migraine. METHODS: We performed genotypic analysis for factor V G1691A, factor II G20210A, methylenetetrahydrofolate reductase C677T, and 4 common platelet glycoprotein polymorphisms (human platelet alloantigen-1, -2, -3, and -5) in 150 children <18 years of age with established diagnoses of stroke, transient ischemic attack, or migraine. Children were classified into 5 groups, namely, childhood arterial ischemic stroke (N = 33), perinatal arterial ischemic stroke (N = 26), hemorrhagic stroke (N = 20), transient ischemic attack (N = 36), and migraine (N = 35). The control group consisted of 112 children < or =18 years of age from the same geographical region who had no history of neurologic or thromboembolic diseases. RESULTS: Heterozygosity for factor V G1691A was associated with approximately sevenfold increased risk for arterial ischemic stroke, perinatal arterial ischemic stroke, and transient ischemic attack. Increased risk for transient ischemic attack was found in carriers of the human platelet alloantigen-2b allele, human platelet alloantigen-5a/b genotype, and combined human platelet alloantigen-2b and human platelet alloantigen-5b genotype. The presence of the human platelet alloantigen-2b allele was associated with a 2.23-fold increased risk for migraine, whereas carriers of the human platelet alloantigen-3b allele had a lower risk for arterial ischemic stroke than did carriers of the human platelet alloantigen-3a allele. CONCLUSIONS: Factor V G1691A has an important role in susceptibility to arterial ischemic stroke, both in the perinatal/neonatal period and in childhood, as well as transient ischemic attacks. A minor impact of human platelet alloantigen polymorphisms suggests that platelet glycoprotein polymorphisms may increase the risk of transient ischemic attacks and migraine, but this should be confirmed in larger studies.