Isolation and partial characterization of a human prothrombin variant: prothrombin Barcelona

An abnormal prothrombin variant, Prothrombin Barcelona, has been isolated by chromatography on DEAE Sephadex, from several members of the same family. In the absence of any normal component, it was eluted in two unequal peaks. The second peak was homogeneous. This component had the same molecular weight as normal prothrombin but migrated slightly faster on disc gel electrophoresis. The first peak, the smaller one, was heterogeneous: in addition to a minor band similar to that of the second peak, a major one with less anodic mobility and with a molecular weight of 32,000 was found. A possible chromatographic artefact has been eliminated. The family study gave good arguments for an heterozygote state of both parents, the siblings being homozygote.