(A) PCR amplification of platelet cDNA (RT-mRNA) using primers flanking exons 9 and 14 shows a 913-bp fragment in a control (WT) and a 302-bp fragment in the proband (P) and her father (F ). The molecular weight marker pBR322 DNA cleaved with Alu I (M) is in the left lane. (B) Nucleotide sequence analysis of the mutant cDNA showing that exon 9 is followed by exon 14. (C) A schematic representation of both normal and mutant genes and their respective mRNA splicings. Because the large deletion includes the AG acceptor site of exon 13, exon 9 is spliced directly to exon 14, skipping the remaining part of exon 13. Direct splicing of exon 9 to 14 in the mutant cDNA is predicted to cause a shift in the reading frame, creating a stop codon after 6 abberant amino acids.