DNA sequencing of PCR products with abnormal ddF patterns. The arrows indicate the locations of nucleotides that differ from the published sequence for wild-type human factor XI.28 (A) exon 5: C to T at nucleotide 472, no amino acid change; (B) exon 5: G to T at nucleotide 446, changing glutamic acid 117 to a stop codon; (C) exon 7: A to G at nucleotide 774, changing glutamine 226 to arginine; (D) exon 8: G to A (top arrow) at nucleotide 840, changing serine 248 to glutamine and A to G (bottom arrow) at nucleotide 844, no amino acid change; (E) exon 9: T to C at nucelotide 944, changing phenylalanine 283 to leucine; and (F) exon 11: T to C at nucleotide 1234, no amino acid change.