Expression at the mRNA level of the FV genes bearing the Leiden mutation (R506Q) and the FV defect (Y1702C), respectively, relative to a normal (Nor) FV allele.

Primers P3, P4, and P5 are used to amplify a nested FV cDNA fragment spanning exons 12 to 13 and containing a polymorphic TaqI restriction site. The 382-bp uncleaved cDNA, corresponding to the A allele of the TaqI polymorphism, marks the FV R506Q allele in subject III4 and the FV Y1702C allele in subject III5; the 346-bpTaqI restriction product, corresponding to the G allele of the TaqI polymorphism, marks the normal (Nor) FV allele in both subjects. The gene and cDNA schemes are drawn to different scales. IVS 12, intron 12.