Recombinant-derived missense mutations in FVIII demonstrate a similar phenotype to described patient plasmas.

(A) One-stage (▪) and 2-stage (■) activity assays from plasmas obtained from hemophilia A patients with these missense mutations as reported in the hemophilia A mutation database. (B) Full-length cDNAs containing missense mutations generated by oligonucleotide site-directed mutagenesis were expressed in COS-1 monkey kidney cells. The data from recombinant-derived protein was obtained from assaying the activity in the conditioned medium at 64 hours following transfection. One-stage activity (▪) was determined by aPTT-based assay. Two-stage activity (■) was determined by COAMATIC assay. Specific activities for recombinant-derived proteins are presented as a percent of recombinant FVIII WT specific activity.