Ischaemic stroke in infancy and childhood: Role of the Arg(506) to Gln mutation in the factor V gene

Dahlback et al. recently described in vitro resistance to the anticoagulant response of activated protein C (APC), in the majority of cases associated with the Arg(506) to Gln point mutation in the factor V gene in thrombophilic patients. To determine to what extent this common gene mutation affects the risk of childhood stroke, its occurrence was prospectively investigated in a population of children with ischaemic stroke, Over a 2-year period the Arg(506) to Gln mutation, factor V, protein C, protein S, antithrombin, antiphospholipid antibodies and lipopoprotein (a) [Lp(a)] were measured in 14 infants and children with acute ischaemic stroke. Heterozygous factor V Leiden mutation (n = 4), homozygous factor V Leiden mutation (n = 1), protein C deficiency type I (n = 3) and increased Lp(a) (n = 2) were diagnosed in the children investigated. Seven of 1 I patients showed an underlying disease and additionally risk factors were present in nine of 14 children. Data of this study indicate that deficiencies in the protein C anticoagulant pathway play an important role in the aetiology of childhood stroke. However, additional triggering factors may promote early manifestation of thromboembolism in children with inherited defects of clotting inhibitors.