Antiphospholipid syndrome in a child with trisomy 21: the relationship between anticardiolipin G antibodies and the von Willebrand factor.

A young child with trisomy 21 developed severe multiple arterial thromboses in a three-phase clinical course which proved fatal. The episodes were characterized by high levels of both IgG anticardiolipin antibodies and the von Willebrand factor. The data suggest that there is a relationship between these two elements and the clinical events which followed.