The effects of VKORC1 SNPs on RNA splicing and mRNA levels. (A) Relative amounts of 3 splice variants of VKORC1 in 65 liver samples. The splice variants were measured by PCR using fluorescently labeled primers. (B) Splice variants of VKORC1 in 4 cell lines after transfection with the entire transcribed region of VKORC1. Haplotype A (1173 T, 1542 C, 2255 T) or haplotype B (1173 C, 1542 G, 2255 C) in pcDNA vector was transfected separately into different cell lines, and VKORC1 splice variants measured. (C) Allelic RNA expression of VKORC1 in 4 cell lines after cotransfection with VKORC1 haplotype A and B, using 3730A>G as marker. Haplotype B contains the 3730 G allele, whereas haplotype A contains the 3730 A allele. Data are means plus or minus SD.