mRNA analysis of proband with activation of cryptic exon 10 splicing from 1701G>T.

(A) Reverse transcription–PCR products of factor V cDNA spanning exon 10 and including part of exons 9 and 11. The expected wild-type product in the control (Ctr) measures 293 bp, whereas the patient (Pt) has a 35-bp deletion and a product size of only 258 bp. Neg indicates reagent control in RT-PCR; Ld, ladder. (B) Sequence tracing of the affected area in the proband's mutant cDNA and protein product, compared with the wild-type factor V cDNA from the same region. The sequence shown in bold reflects the 3′ exon 10 segment, which is illegitimately spliced out in the patient.